1998 Vol. 20, No. 6
Display Method:
1998, 20(6): 1-11.
Abstract:
Based on the hydrographic data of the four cruises in 1992,a modified inverse method is used to compute the velocity,volume and heat transports of the Kuroshio in the East China Sea.The computed results show that:(1)There are two current cores of the Kuroshio at Section PN in spring and autumn,but one core in winter and summer.The main core always lies over the shelf break.The Kuroshio is strongest in spring.secondary in winter and summer and weakest in autumn.There are also countercurrents under and east of the Kuroshio at Section PN.(2) There are two current cores of the Kuroshio at Section TK in winter,three cores in spring and summer.Countercurrent,exist in the southern part and the deep layer of the Tokara Strait.(3) The Tsushima Warm Current(TSWC)at Section A is strongest in autumn and weakest in winter,and is stronger than the Huanghai Warm Current which lies to the west of the TSWC.(4)The net northeastward volume transport (hereafter VT) through Section PN is largest in summer and,mallet in autumn with an average of 28.0×106m3/s in the four cruises of 1992.the net eastward VT at Section TK is also largest in summer.The net northward VT at Section A is largest in autumn.(5) The average heat transport through Section PN during the four cruises is 2.03×1015 W,and that through Section TK is 2.00×1015 W during the three cruises.(6) In the computation area,heat transfer is from the ocean to the atmosphere during winter.spring and autumn,but from the atmosphere to the cxean in summer.The average rate of heat transfer is largest in winter,but smallest in summer.
Based on the hydrographic data of the four cruises in 1992,a modified inverse method is used to compute the velocity,volume and heat transports of the Kuroshio in the East China Sea.The computed results show that:(1)There are two current cores of the Kuroshio at Section PN in spring and autumn,but one core in winter and summer.The main core always lies over the shelf break.The Kuroshio is strongest in spring.secondary in winter and summer and weakest in autumn.There are also countercurrents under and east of the Kuroshio at Section PN.(2) There are two current cores of the Kuroshio at Section TK in winter,three cores in spring and summer.Countercurrent,exist in the southern part and the deep layer of the Tokara Strait.(3) The Tsushima Warm Current(TSWC)at Section A is strongest in autumn and weakest in winter,and is stronger than the Huanghai Warm Current which lies to the west of the TSWC.(4)The net northeastward volume transport (hereafter VT) through Section PN is largest in summer and,mallet in autumn with an average of 28.0×106m3/s in the four cruises of 1992.the net eastward VT at Section TK is also largest in summer.The net northward VT at Section A is largest in autumn.(5) The average heat transport through Section PN during the four cruises is 2.03×1015 W,and that through Section TK is 2.00×1015 W during the three cruises.(6) In the computation area,heat transfer is from the ocean to the atmosphere during winter.spring and autumn,but from the atmosphere to the cxean in summer.The average rate of heat transfer is largest in winter,but smallest in summer.
1998, 20(6): 12-20.
Abstract:
By using wavelet transform (WT),we analysed part of the LTD data collected from the equatorial western Pacific Ocean,the results show that the temperature finestructures has selfsimilarity and may be described with fractal.The singularity exponents of temperature series and their probability distributions are also calculated.The probability distribution functions (pdfs) have nearly a universal form.The nonzero probability at negative exponents implies the possible existence of singular points in the temperature profiles.When computing the average period of the WT,we found that the mean period △ of WT of the temperature series has a power dependence on the transform scale u,that is,△～αβ with β≈1.This nuggests that a simple dichomotous cascading mechanism may govern the finestructure dynamics.In addtion,since the amplitude to of the wavelet transform is related with the strength of temperature fluctuations,the vertical distribution of fluctuation energy can be calculated with wavelet transform.Compared to the FFT spectrum,the WT spectrum is more smooth and is capable of giving more accurate spectral slope.
By using wavelet transform (WT),we analysed part of the LTD data collected from the equatorial western Pacific Ocean,the results show that the temperature finestructures has selfsimilarity and may be described with fractal.The singularity exponents of temperature series and their probability distributions are also calculated.The probability distribution functions (pdfs) have nearly a universal form.The nonzero probability at negative exponents implies the possible existence of singular points in the temperature profiles.When computing the average period of the WT,we found that the mean period △ of WT of the temperature series has a power dependence on the transform scale u,that is,△～αβ with β≈1.This nuggests that a simple dichomotous cascading mechanism may govern the finestructure dynamics.In addtion,since the amplitude to of the wavelet transform is related with the strength of temperature fluctuations,the vertical distribution of fluctuation energy can be calculated with wavelet transform.Compared to the FFT spectrum,the WT spectrum is more smooth and is capable of giving more accurate spectral slope.
1998, 20(6): 21-30.
Abstract:
The sensible and latent heat fluxes over the ocean area near China were calculated and analyzed by using the Uoddard Earth Observing System (GEOS)-Four-Dimensional Data Assimilation System (DAS).The calculated results showed that the sensible heat flux had its large value in winter and autumn,small value in spring and summer over the ocean area near China.In winter,the sensible heat flux increased distinctly with latitulle,and its isolines were very crowded.Over the ocean area east of Taiwan and south of Japan,the direction of isoline was from southwest to northeast.In the South China Sea,the sensible heat flux was lower than that of surrounding ocean areas,and its isoline was distributed into a type of an inverted trough.In autumn and winter,the maximum center of latent heat flux appeared over the ocean area northeast of Taiwan and south and southeast of Japan,meanwhile,the isoline was in the direction of southwest to northeast.In spring and summer,the latent heat flux had minimum value in the Huanghai Sea: At the same time,the maximum value center of latent heat flux appeared over the ocean area south of Japan in spring.
The sensible and latent heat fluxes over the ocean area near China were calculated and analyzed by using the Uoddard Earth Observing System (GEOS)-Four-Dimensional Data Assimilation System (DAS).The calculated results showed that the sensible heat flux had its large value in winter and autumn,small value in spring and summer over the ocean area near China.In winter,the sensible heat flux increased distinctly with latitulle,and its isolines were very crowded.Over the ocean area east of Taiwan and south of Japan,the direction of isoline was from southwest to northeast.In the South China Sea,the sensible heat flux was lower than that of surrounding ocean areas,and its isoline was distributed into a type of an inverted trough.In autumn and winter,the maximum center of latent heat flux appeared over the ocean area northeast of Taiwan and south and southeast of Japan,meanwhile,the isoline was in the direction of southwest to northeast.In spring and summer,the latent heat flux had minimum value in the Huanghai Sea: At the same time,the maximum value center of latent heat flux appeared over the ocean area south of Japan in spring.
1998, 20(6): 31-38.
Abstract:
One hundred and eighty one aerosol samples,and two cascade impactor samples were collected in the atmosphere over the western Taiwan Strait from 1991 to 1993.Concentrations of Al,Fe.Cu,Pb,Cd,and Na were determined by an atomic absorption spectrophotometry.The contents of Fe,Cu,Pb and Cd in the atmosphere over the western Taiwan Strait were lower than those over inland cities in China,Europe or North America.Annual and seasonal variations of concentrations of the metals could be primarily attributed to washout or monsoon for non sea salt metals.Fe was presented in bimodel distributions with size around 3.6 μm and 0.52μm Al was chiefly distributed on the particles with size less than 2.1 μm,Na on the particles with size greater than or equal to 3.6 μm,and the size distributions of Cu,Pb and Cd were presented in small particles.chiefly on those with size less than or equal to 0.52 μm.
One hundred and eighty one aerosol samples,and two cascade impactor samples were collected in the atmosphere over the western Taiwan Strait from 1991 to 1993.Concentrations of Al,Fe.Cu,Pb,Cd,and Na were determined by an atomic absorption spectrophotometry.The contents of Fe,Cu,Pb and Cd in the atmosphere over the western Taiwan Strait were lower than those over inland cities in China,Europe or North America.Annual and seasonal variations of concentrations of the metals could be primarily attributed to washout or monsoon for non sea salt metals.Fe was presented in bimodel distributions with size around 3.6 μm and 0.52μm Al was chiefly distributed on the particles with size less than 2.1 μm,Na on the particles with size greater than or equal to 3.6 μm,and the size distributions of Cu,Pb and Cd were presented in small particles.chiefly on those with size less than or equal to 0.52 μm.
1998, 20(6): 39-43.
Abstract:
A new experiential formula of the relationship between the sound velocity Vp Ccompressional wave)in the sea-floor sediments of the continental shelf and its porosity n is given.When n=100,Vp=V0,V0 is sound velocity of sea water closed to sea bed.Experimental results on continental shelf of China neighborhood obtained by this formula are better than those of other formulae.
A new experiential formula of the relationship between the sound velocity Vp Ccompressional wave)in the sea-floor sediments of the continental shelf and its porosity n is given.When n=100,Vp=V0,V0 is sound velocity of sea water closed to sea bed.Experimental results on continental shelf of China neighborhood obtained by this formula are better than those of other formulae.
1998, 20(6): 44-49.
Abstract:
A cell designed to produce an anaerobic experimental environment modelling sea bed sediments was used to study the effects of temperature and resistivity on the electrode process and the effects of temperature,resistivity and sulphate reducing bacteria on the corrosion of steel in sediments.The results show that the catholic and anodic process of steel in sediments will conduct more easy when the temperature raises or the resistivity relutes,and the corrosion of steel will quicken in varying degrees in sediments when the temperature raises or the resistivity reduces or the sulphate reducing bacteria content raises.
A cell designed to produce an anaerobic experimental environment modelling sea bed sediments was used to study the effects of temperature and resistivity on the electrode process and the effects of temperature,resistivity and sulphate reducing bacteria on the corrosion of steel in sediments.The results show that the catholic and anodic process of steel in sediments will conduct more easy when the temperature raises or the resistivity relutes,and the corrosion of steel will quicken in varying degrees in sediments when the temperature raises or the resistivity reduces or the sulphate reducing bacteria content raises.
1998, 20(6): 50-57.
Abstract:
The activity of 224Ra in the seawater from the Xiamen Bay was determined by preconcentration with MnUz-fiber and successive emanation scintillation method of 220Rn.The profiles of 224Ra were applied to the estimation of the vertical eddy diffusion coefficient (Kz) at the several stations in the Xiamen Bay.The profiles of 224Ra and Kz arising therefrom make it possible to gain an insight into the pattern of the vertical diffusion of the waters in sea area studied and its spatial and temporal variations.These results will provide guidances for the study on the diffusion and transport of dissolved pollutant and estimation of self-purification capacity of the sea area studied.
The activity of 224Ra in the seawater from the Xiamen Bay was determined by preconcentration with MnUz-fiber and successive emanation scintillation method of 220Rn.The profiles of 224Ra were applied to the estimation of the vertical eddy diffusion coefficient (Kz) at the several stations in the Xiamen Bay.The profiles of 224Ra and Kz arising therefrom make it possible to gain an insight into the pattern of the vertical diffusion of the waters in sea area studied and its spatial and temporal variations.These results will provide guidances for the study on the diffusion and transport of dissolved pollutant and estimation of self-purification capacity of the sea area studied.
1998, 20(6): 58-69.
Abstract:
Water is higher turbidity and turbidity maximum occurs in the Jiaojiang Estuary.Typical concentration profile is often present in turbidity maximum.There is three order of magnitude range in concentration from the surface to the seabed,i.e.mobile suspended layer,lutocline and fluid mud.It is noted that three layers in concentration vertical profile develops the most clear during neap tide in winter.
Water is higher turbidity and turbidity maximum occurs in the Jiaojiang Estuary.Typical concentration profile is often present in turbidity maximum.There is three order of magnitude range in concentration from the surface to the seabed,i.e.mobile suspended layer,lutocline and fluid mud.It is noted that three layers in concentration vertical profile develops the most clear during neap tide in winter.
1998, 20(6): 70-75.
Abstract:
Based on regional compensation and experimental isostasy,the calculating formula of theoretical isostatic response function is deduced when the loads on top correlate with loads from below.A variety of curves of theoretical isostatic response function was calculated with different effective elastic thickness of the plate and by using different proportions between loads on top and loads from below.And preliminary discussion is made on shapes of the curves.
Based on regional compensation and experimental isostasy,the calculating formula of theoretical isostatic response function is deduced when the loads on top correlate with loads from below.A variety of curves of theoretical isostatic response function was calculated with different effective elastic thickness of the plate and by using different proportions between loads on top and loads from below.And preliminary discussion is made on shapes of the curves.
1998, 20(6): 76-80.
Abstract:
Based on regional compensation model and experimental isostasy,the isostatic response function of the Okinawa Trough was calculated by using gravity and topographic data.The results are shown as follows: the effective elastic thickness of the plate and compensation depth in the southern Ukinawa Trough is obviously greater than those in the middle Okinawa Trough.In reference with other geological and geophysical data,the deferences between the two portions are explained to be caused mainly by their differences in temperature of the lithosphere and the compensation mechanism.
Based on regional compensation model and experimental isostasy,the isostatic response function of the Okinawa Trough was calculated by using gravity and topographic data.The results are shown as follows: the effective elastic thickness of the plate and compensation depth in the southern Ukinawa Trough is obviously greater than those in the middle Okinawa Trough.In reference with other geological and geophysical data,the deferences between the two portions are explained to be caused mainly by their differences in temperature of the lithosphere and the compensation mechanism.
1998, 20(6): 81-86.
Abstract:
The distribution of bacteria number was investigated in the Pacific Ocean and the Pryts Bay of the Antarctica and its adjacent waters.Some of environmental factors to effect the bacterial numbers are discussed.The investigated results show that the bacterial number in the surveyed zone varied between 107～108dm-3.It is found the bacterial number of the middle Pacific Ucean zone was as much as that in eastern and western waters of the Pacific Ocean.This is due to the biological nutrients material here more than higher the another zone of the Pacific Ocean,the number of bacreria with some of the section water such as Station P23 and Station P18 (0~50 m or 500~700 m deep) more than higher the other section waters at the same deep layer waters.As a result of effect of water dynamics in these deep layer water.Also it is found that the bacterial numbers in some section waters have increase more and more high trend from continental borderland to sea waters forward stretching in the Pryts Bay of the Antarctica.
The distribution of bacteria number was investigated in the Pacific Ocean and the Pryts Bay of the Antarctica and its adjacent waters.Some of environmental factors to effect the bacterial numbers are discussed.The investigated results show that the bacterial number in the surveyed zone varied between 107～108dm-3.It is found the bacterial number of the middle Pacific Ucean zone was as much as that in eastern and western waters of the Pacific Ocean.This is due to the biological nutrients material here more than higher the another zone of the Pacific Ocean,the number of bacreria with some of the section water such as Station P23 and Station P18 (0~50 m or 500~700 m deep) more than higher the other section waters at the same deep layer waters.As a result of effect of water dynamics in these deep layer water.Also it is found that the bacterial numbers in some section waters have increase more and more high trend from continental borderland to sea waters forward stretching in the Pryts Bay of the Antarctica.
1998, 20(6): 87-100.
Abstract:
Based on Navier-Stokes equation,the model equation is deduced through a-coordinate transformation,then by selecting a series of the specific interpolation value function,using the combined method of the finite element and the difference,solution is obtained,the model is very suitable for calculating tide current in the sea area with complex bank boundaries or harbour engineering construction,which also can achieve densifying calculation in local or partial region and can reveal the space structure characteristics of the three-dimensional tide current with higher distinguishable rate,the model has many advantages such as being simple to application and saving calculation time.
Based on Navier-Stokes equation,the model equation is deduced through a-coordinate transformation,then by selecting a series of the specific interpolation value function,using the combined method of the finite element and the difference,solution is obtained,the model is very suitable for calculating tide current in the sea area with complex bank boundaries or harbour engineering construction,which also can achieve densifying calculation in local or partial region and can reveal the space structure characteristics of the three-dimensional tide current with higher distinguishable rate,the model has many advantages such as being simple to application and saving calculation time.
1998, 20(6): 101-108.
Abstract:
A nonlinear fatigue damage model is investigated.Both genetic algorithms and evolutionary programming are applied to the fatigue reliability-based optimum design of a simple offshore platform.The reliability of the fatigue damage model and the effectiveness of genetic algorithms and evolutionary programming which are used are shown by the results of optimum design.Some characteristics of genetic algorithms and evolutionary programming are discussed.
A nonlinear fatigue damage model is investigated.Both genetic algorithms and evolutionary programming are applied to the fatigue reliability-based optimum design of a simple offshore platform.The reliability of the fatigue damage model and the effectiveness of genetic algorithms and evolutionary programming which are used are shown by the results of optimum design.Some characteristics of genetic algorithms and evolutionary programming are discussed.
1998, 20(6): 109-116.
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1998, 20(6): 117-123.
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1998, 20(6): 124-131.
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1998, 20(6): 132-138.
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1998, 20(6): 139-144.
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