1999 Vol. 21, No. 5
Display Method:
1999, 21(5): 1-11.
Abstract:
Hydrographic features and circulation situation in the southern Huanghai Sea (SHS) are studied on the basis of the data obtained by China-Korea Joint Investigation of Ocean Circulation Dynamics in the SHS in the early spring of 1996,The main results are as follows:(1) The temperature-salinity characteristics and the basic circulation pattern in the SHS in the early spring are basically similar to those in winter revealed in the past,However,it is found in this investigation that the axis of the warm water tongue in the middle Huanghai Sea is obviously to the east as compared with wintertime situation and a small-range isolated water body with relatively high temperature and salinity appears in this region,Meanwhile,a middle-layer cold water and a surface inversion layer occur in the local regions of the SHS; (2) the results of direct current measurements not only verify the basic pattern of the circulation showing by temperature-salinity distributions,but also reveal much better some new phenomena occurring in the current field,especially the current around Cheju-do; (3) the Huanghai Warm Current water is a mixture of the Tsushima Warm Current water and the continental shelf water and originates mainly from the frontal region west of Cheju-do.
Hydrographic features and circulation situation in the southern Huanghai Sea (SHS) are studied on the basis of the data obtained by China-Korea Joint Investigation of Ocean Circulation Dynamics in the SHS in the early spring of 1996,The main results are as follows:(1) The temperature-salinity characteristics and the basic circulation pattern in the SHS in the early spring are basically similar to those in winter revealed in the past,However,it is found in this investigation that the axis of the warm water tongue in the middle Huanghai Sea is obviously to the east as compared with wintertime situation and a small-range isolated water body with relatively high temperature and salinity appears in this region,Meanwhile,a middle-layer cold water and a surface inversion layer occur in the local regions of the SHS; (2) the results of direct current measurements not only verify the basic pattern of the circulation showing by temperature-salinity distributions,but also reveal much better some new phenomena occurring in the current field,especially the current around Cheju-do; (3) the Huanghai Warm Current water is a mixture of the Tsushima Warm Current water and the continental shelf water and originates mainly from the frontal region west of Cheju-do.
1999, 21(5): 12-21.
Abstract:
Based on the CTD data obtained from China-Korea Joint Investigation in October 1996,the characteristics of thermocline and vertical mixture in the southern Huanghai Sea in autumn are analysed,and the vertical mixture in the Huanghai Sea Cold Water Mass area is preliminarily discussed,The cluster analysis and Bayes multistage discrimination methods are used to classify the surface and bottom water masses and define the average characteristic values of temperature,salinity,dissolved oxygen and pH for different water masses,The discussions are focused on the mixture and exchange of the Huanghai Sea water with the coastal water and the East China Sea water according to the distributions of temperature and salinity,and the characteristics of different water masses.
Based on the CTD data obtained from China-Korea Joint Investigation in October 1996,the characteristics of thermocline and vertical mixture in the southern Huanghai Sea in autumn are analysed,and the vertical mixture in the Huanghai Sea Cold Water Mass area is preliminarily discussed,The cluster analysis and Bayes multistage discrimination methods are used to classify the surface and bottom water masses and define the average characteristic values of temperature,salinity,dissolved oxygen and pH for different water masses,The discussions are focused on the mixture and exchange of the Huanghai Sea water with the coastal water and the East China Sea water according to the distributions of temperature and salinity,and the characteristics of different water masses.
1999, 21(5): 22-30.
Abstract:
On the basis of the observations of temperature and salinity in the winter and summer of 1967-1995 at 137°E section,geostropica flow is calculated and the Subtropical Countercurrent(SCC)analysed at this section,Main results are as follows:(1) The SCC appears in both winter and summer and exists in the forms of one,two,three or four subbranches in winter and in the forms of two,three subbranches in summer,However,the form of two subbranches dominates in both seasons,(2) The SCC mainly appears between 22°-23°N and 26°-27°N in winter and between 21-22°N and 24°-25°N in summer,(3) The velocity of the SCC takes in a band structure,mostly in the form of a single bunch and single core and a very few in the form of a single bunch and double cores,The velocity is strong in summer and weak in winter,(4) The interannual variation of the volume transport of the SCC is much large,In regard to multi-year mean value,the volume transport is 14,3×106 m3/s in winter and 22,9×10M6 m3/s in summer,(5) In winter,the original area of the SCC is same as that of the Kuroshio and is a branch of the Kuroshio east of Tawain Province,the flowing eastword along the margin of the warm ridge and the cold trough.
On the basis of the observations of temperature and salinity in the winter and summer of 1967-1995 at 137°E section,geostropica flow is calculated and the Subtropical Countercurrent(SCC)analysed at this section,Main results are as follows:(1) The SCC appears in both winter and summer and exists in the forms of one,two,three or four subbranches in winter and in the forms of two,three subbranches in summer,However,the form of two subbranches dominates in both seasons,(2) The SCC mainly appears between 22°-23°N and 26°-27°N in winter and between 21-22°N and 24°-25°N in summer,(3) The velocity of the SCC takes in a band structure,mostly in the form of a single bunch and single core and a very few in the form of a single bunch and double cores,The velocity is strong in summer and weak in winter,(4) The interannual variation of the volume transport of the SCC is much large,In regard to multi-year mean value,the volume transport is 14,3×106 m3/s in winter and 22,9×10M6 m3/s in summer,(5) In winter,the original area of the SCC is same as that of the Kuroshio and is a branch of the Kuroshio east of Tawain Province,the flowing eastword along the margin of the warm ridge and the cold trough.
1999, 21(5): 31-37.
Abstract:
Relationships between the mean wavelength and mean wave-period of wind waves are derived for fetch-limited and ful-ly developed sea states represented by mean JONSWAP spectrum and P-M spectrum,respectively,and found to be ,The derivations start from the Rice solution of zero-crossirtt; problem and the spectral moment of 4-orders involved in the derivations are estimated through a time-averaging technique,Experiments have been conducted }n a wind-wave channel,The experimented results are compared with the derived relationship,showing a favorable agreement.
Relationships between the mean wavelength and mean wave-period of wind waves are derived for fetch-limited and ful-ly developed sea states represented by mean JONSWAP spectrum and P-M spectrum,respectively,and found to be ,The derivations start from the Rice solution of zero-crossirtt; problem and the spectral moment of 4-orders involved in the derivations are estimated through a time-averaging technique,Experiments have been conducted }n a wind-wave channel,The experimented results are compared with the derived relationship,showing a favorable agreement.
1999, 21(5): 38-45.
Abstract:
The atmospheric input of aerosols from the continent of Asia to the eastern seas of China are investigated,using aerosol data collected over the Huanghai Sea,the East China Sea and the sea area south to Japan,The main results are as follows:the monthly mean dry deposition fluxes of aluminium-a representative element of dust over the Huanghai Sea,the East China Sea and the sea area south to Japan are 42.8,18.3 and 5.2 mg/m2 respectively; the corresponding monthly mean total deposition fluxes are 54.1,29.8 and 10.5 mg/m2,The annually mean atmospheric depositions of dust aerosol to the Bohai Sea,the Huanghai Sea,the East China Sea and the sea area south to Japan are 26.4,9.3,5,1 and 1.8 g/m2 respectively,Over the East China Sea,the seasonal pattern of the total deposition flux for pollution element is the highest in spring,moderate in autumn and winter,and the lowest in summer,Over the sea area south to Japan,the highest total deposition flux of Sb appeared in winter,moderate in summer and spring,and the lowest in autumn; the highest total deposition flux of Se appeared in summer.
The atmospheric input of aerosols from the continent of Asia to the eastern seas of China are investigated,using aerosol data collected over the Huanghai Sea,the East China Sea and the sea area south to Japan,The main results are as follows:the monthly mean dry deposition fluxes of aluminium-a representative element of dust over the Huanghai Sea,the East China Sea and the sea area south to Japan are 42.8,18.3 and 5.2 mg/m2 respectively; the corresponding monthly mean total deposition fluxes are 54.1,29.8 and 10.5 mg/m2,The annually mean atmospheric depositions of dust aerosol to the Bohai Sea,the Huanghai Sea,the East China Sea and the sea area south to Japan are 26.4,9.3,5,1 and 1.8 g/m2 respectively,Over the East China Sea,the seasonal pattern of the total deposition flux for pollution element is the highest in spring,moderate in autumn and winter,and the lowest in summer,Over the sea area south to Japan,the highest total deposition flux of Sb appeared in winter,moderate in summer and spring,and the lowest in autumn; the highest total deposition flux of Se appeared in summer.
1999, 21(5): 46-58.
Abstract:
The velocity data measured by the acoustic Doppler velocimeter (ADV) and the wave surface data measured by a wave gage array are used to analyse the directional spectrum of wave generated with a segmented wavemaker,The results show that (1) the steadiness of 3-D random waves in time domain is better than their homogeneity in spatial domain; (2) Bayesian approach (BDM) is available for directional spectrum analysis from velocity data and wave surface data; (3) the directional spectrum analysed from velocity data has the same accuracy as that analysed from wave surface data and (4) the directional spectrum with appropriate accuracy can be obtained from three wave parameters,such as three wave surfaces,two component velocities and one wave surface.The preliminary criterion for measuring the accuracy of directional spectrum analysis is proposed.
The velocity data measured by the acoustic Doppler velocimeter (ADV) and the wave surface data measured by a wave gage array are used to analyse the directional spectrum of wave generated with a segmented wavemaker,The results show that (1) the steadiness of 3-D random waves in time domain is better than their homogeneity in spatial domain; (2) Bayesian approach (BDM) is available for directional spectrum analysis from velocity data and wave surface data; (3) the directional spectrum analysed from velocity data has the same accuracy as that analysed from wave surface data and (4) the directional spectrum with appropriate accuracy can be obtained from three wave parameters,such as three wave surfaces,two component velocities and one wave surface.The preliminary criterion for measuring the accuracy of directional spectrum analysis is proposed.
1999, 21(5): 59-64.
Abstract:
A new index for evaluating any kind of fine grain model ice properties is set up based on the physical essence in ice making and model ice,The theoretical basement of the index and the experimental relationships between the index and each mair parameter of the ethanol model ice physical and mechanical properties are given.
A new index for evaluating any kind of fine grain model ice properties is set up based on the physical essence in ice making and model ice,The theoretical basement of the index and the experimental relationships between the index and each mair parameter of the ethanol model ice physical and mechanical properties are given.
1999, 21(5): 65-71.
Abstract:
After preconcentration of Ra isotopes using Mn-fiber adsorption from large volume sea water,the specific activities of 224Ra,226Ra and 228Ra are measured through measuring γ-rays of their daughters by I-IPGe γ-spectrometer,The calculating formulas of specific activities of the three nuclides are derived,The sample preparation and spectrum analysis method are discussed.The advantages of this method are simple,rapid,and three nuclides can be determined simultaneously.
After preconcentration of Ra isotopes using Mn-fiber adsorption from large volume sea water,the specific activities of 224Ra,226Ra and 228Ra are measured through measuring γ-rays of their daughters by I-IPGe γ-spectrometer,The calculating formulas of specific activities of the three nuclides are derived,The sample preparation and spectrum analysis method are discussed.The advantages of this method are simple,rapid,and three nuclides can be determined simultaneously.
1999, 21(5): 72-77.
Abstract:
Based on six cruise's data during 1996-1998 under the project of China-Korea Joint Research on the Seawater Circulation Dynamics in the Huanghai Sea,the features in vertical profiles and seasonal variations of dissolved oxygen in the southern Huanghai Sea are discussed systematically,The regional distribution and formation mechanism of dissolved oxygen maximum in vertical distribution in spring and summer and its relation to summer thermocline and organism activity are also discussed.
Based on six cruise's data during 1996-1998 under the project of China-Korea Joint Research on the Seawater Circulation Dynamics in the Huanghai Sea,the features in vertical profiles and seasonal variations of dissolved oxygen in the southern Huanghai Sea are discussed systematically,The regional distribution and formation mechanism of dissolved oxygen maximum in vertical distribution in spring and summer and its relation to summer thermocline and organism activity are also discussed.
1999, 21(5): 78-86.
Abstract:
Systematical identifying and quantitative counting of planktonic Foratninifera(>0.154 mm) have been carried out for 53 surface sediment samples in the southern Okinawa Trough,The distributional characteristics of each species and assemblage of planktonic Foraminifera are obtained using Q-mode factor analysis,N,dutertrei-P,oblzquiloculata assemblage is mainly distributed in the sea area near The Mainland and Taiwan,China,while G.glutznata-G,Tuber assemblage is distributed in the central part and the Ryūkyū-gunto side of the Okinawa Trough,Moreover,it is found that the distribution and variation of planktonic foraminiferal abundance,assemblage and fragmentation are mainly controlled by the environmental factors such as water depth,carbonate lysocline,thermocline and water masses.
Systematical identifying and quantitative counting of planktonic Foratninifera(>0.154 mm) have been carried out for 53 surface sediment samples in the southern Okinawa Trough,The distributional characteristics of each species and assemblage of planktonic Foraminifera are obtained using Q-mode factor analysis,N,dutertrei-P,oblzquiloculata assemblage is mainly distributed in the sea area near The Mainland and Taiwan,China,while G.glutznata-G,Tuber assemblage is distributed in the central part and the Ryūkyū-gunto side of the Okinawa Trough,Moreover,it is found that the distribution and variation of planktonic foraminiferal abundance,assemblage and fragmentation are mainly controlled by the environmental factors such as water depth,carbonate lysocline,thermocline and water masses.
1999, 21(5): 87-94.
Abstract:
An approach combining field data with remote sensing data to study the coastal stability is developed,Problems,such as tide field,sediment movement and distribution and tideland for cultivation are discussed,The results demonstrate that the and the beach of the Sanmen Bay are basically steady under the condition of limited cultivation.
An approach combining field data with remote sensing data to study the coastal stability is developed,Problems,such as tide field,sediment movement and distribution and tideland for cultivation are discussed,The results demonstrate that the and the beach of the Sanmen Bay are basically steady under the condition of limited cultivation.
1999, 21(5): 95-100.
Abstract:
The tilt movement of the Ryukyu island-arc system toward the ocean trench and the waving movement of the mantle stream in the island-arc-back-arc area are the power source of the movement of the Okinawa Trough,The Okinawa Trough is a negative structure under the tension field after Tertiary,Modern trough inherits the old trough and develops in its staged style.From Later Miocene,the increase of tension movement of the Okinawa Trough is deeply related to the increment of subduction movement of the Philippine Sea Plate,but this movement cannot cause a large-scale spreading.
The tilt movement of the Ryukyu island-arc system toward the ocean trench and the waving movement of the mantle stream in the island-arc-back-arc area are the power source of the movement of the Okinawa Trough,The Okinawa Trough is a negative structure under the tension field after Tertiary,Modern trough inherits the old trough and develops in its staged style.From Later Miocene,the increase of tension movement of the Okinawa Trough is deeply related to the increment of subduction movement of the Philippine Sea Plate,but this movement cannot cause a large-scale spreading.
1999, 21(5): 101-109.
Abstract:
The species composition,quantity distribution and community structure are analyzed,All of 314 species of macrobenthos have been identified in the Xinghua Bay,Fujian,The average biomass is 36.60 g/m2,the inhabited density is 162 ind,/m2.There are four communities of macrobenthos in the Xinghua Bay which are divided according to Bray-Curtis similarity and multidimensional scaling ordination,The relatively stability of communities are shown based on abundance biomass comparison method and species individual geometric progression.
The species composition,quantity distribution and community structure are analyzed,All of 314 species of macrobenthos have been identified in the Xinghua Bay,Fujian,The average biomass is 36.60 g/m2,the inhabited density is 162 ind,/m2.There are four communities of macrobenthos in the Xinghua Bay which are divided according to Bray-Curtis similarity and multidimensional scaling ordination,The relatively stability of communities are shown based on abundance biomass comparison method and species individual geometric progression.
1999, 21(5): 110-119.
Abstract:
The feeding habits and the growth of larval,juvenile and young Lateolabrax japonicus are dealt with,The result shows that the larva began to feed about 140 h from hatching at water temperature of 15,5-16.5℃.The initial diet is small Brachionus,The naupliar larva of Chirocephalus can be fed when the larva attained about 10 mm in total length,The Cladocera can be fed when the total length of the larva was about 11 mm,Based upon the determination of 431 individuals,the percentage of stomach with food was 99,1%and the plump coefficient of stomath was 2,38%-16.4896 in the experimental conditions,The diel feeding amount was 45%-60% of the body weight of larval,juvenile and young fish,Rhythm of feeding intensity is obviously different during the day and night,the higher feeding intensity is at 16:00 and 20:00 p,m,Nothing can be fed in the darkness of night during the larval and juvenile stages,and the young fishes can feed a few in the same condition,There are certain differences in growth between the individuals of the larval,juvenile and young fish,The relationship between the feeding amount and body weight is expressed as y=0.1018+8.3261×10-2x,that between the total length and body weight is expressed ω=1.6473×10-3L3.4743 that between total length and day age can be expressed as Lt=5.5242e1.9681×10-2D and that between the body weight and the day age is expressed ω=0.5836e6.9208×10-2D.
The feeding habits and the growth of larval,juvenile and young Lateolabrax japonicus are dealt with,The result shows that the larva began to feed about 140 h from hatching at water temperature of 15,5-16.5℃.The initial diet is small Brachionus,The naupliar larva of Chirocephalus can be fed when the larva attained about 10 mm in total length,The Cladocera can be fed when the total length of the larva was about 11 mm,Based upon the determination of 431 individuals,the percentage of stomach with food was 99,1%and the plump coefficient of stomath was 2,38%-16.4896 in the experimental conditions,The diel feeding amount was 45%-60% of the body weight of larval,juvenile and young fish,Rhythm of feeding intensity is obviously different during the day and night,the higher feeding intensity is at 16:00 and 20:00 p,m,Nothing can be fed in the darkness of night during the larval and juvenile stages,and the young fishes can feed a few in the same condition,There are certain differences in growth between the individuals of the larval,juvenile and young fish,The relationship between the feeding amount and body weight is expressed as y=0.1018+8.3261×10-2x,that between the total length and body weight is expressed ω=1.6473×10-3L3.4743 that between total length and day age can be expressed as Lt=5.5242e1.9681×10-2D and that between the body weight and the day age is expressed ω=0.5836e6.9208×10-2D.
A preliminary study on ecology of phytoplankton in the subtropic gyre zone during the spring of 1996
1999, 21(5): 120-128.
Abstract:
A total of 184 phytoplankton species which belong respectively to 54 genera is identified,Most of those species recorded belonged to warm water forms (accounted for 76,5%).The cell density of diatoms and dinoflagellates averaged 198.71×102 cells/m3,The filament density of blue-green algae averaged 44.55×102 filaments/m3,The distribution of each group of phytoplankton is correlated to both phosphate concentration in sea water and the influence of Kuroshio and other water systems(upwelling and coastal water,etc.)etc,The distribution of blue-green alga Trichodesrniurn has close correlation to the mean water temperature in the upper 50 m as well.
A total of 184 phytoplankton species which belong respectively to 54 genera is identified,Most of those species recorded belonged to warm water forms (accounted for 76,5%).The cell density of diatoms and dinoflagellates averaged 198.71×102 cells/m3,The filament density of blue-green algae averaged 44.55×102 filaments/m3,The distribution of each group of phytoplankton is correlated to both phosphate concentration in sea water and the influence of Kuroshio and other water systems(upwelling and coastal water,etc.)etc,The distribution of blue-green alga Trichodesrniurn has close correlation to the mean water temperature in the upper 50 m as well.
1999, 21(5): 129-136.
Abstract:
By means of nonlinear pushover failure analysis method,the aseismic reliability analysis of two offshore jacket platforms is studied according to its ocean location and environmental loading there,On the basis of this,an aseismic reliability analysis approach is presented,The results show that the aseismic reliability index of those platforms is high and the failure probability is very low,Also it is proved that this aseismic reliability analysis approach presented here is rather simple,practical and reliable.
By means of nonlinear pushover failure analysis method,the aseismic reliability analysis of two offshore jacket platforms is studied according to its ocean location and environmental loading there,On the basis of this,an aseismic reliability analysis approach is presented,The results show that the aseismic reliability index of those platforms is high and the failure probability is very low,Also it is proved that this aseismic reliability analysis approach presented here is rather simple,practical and reliable.
1999, 21(5): 137-143.
Abstract:
1999, 21(5): 144-148.
Abstract:
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