2002 Vol. 24, No. 2
Display Method:
2002, 24(2): 1-8.
Abstract:
Based on the characteristic of the self-simulation of the vertical temperature profile and the property that the integral of similarity function is equal to constant at each layer,the sea was divided into 4 layers.The heat conduction equations of similarity function were deduced with considering heating from sea surface and nonheat transform at bottom.The equation set consists of 7 characteristic values of the vertical structure for the intermediate cold water.After these values were calculated,they were substituted to the temperature formulas of the selfsimulating function.The temperature profile can be predicted.In order to examine this model efficacy the hindcastings were done.The effectiveness for a given period of time is 5 d.The results shows that the root-mean square error between the predicted and measured of the characteristic temperature was lower than or equal to 0.23℃,the characteristic depth was lower than or equal to 1.18 m and the profile temperature was lower than or equal to 0.20℃.It is shown that the results of trial prediction are satisfactory.
Based on the characteristic of the self-simulation of the vertical temperature profile and the property that the integral of similarity function is equal to constant at each layer,the sea was divided into 4 layers.The heat conduction equations of similarity function were deduced with considering heating from sea surface and nonheat transform at bottom.The equation set consists of 7 characteristic values of the vertical structure for the intermediate cold water.After these values were calculated,they were substituted to the temperature formulas of the selfsimulating function.The temperature profile can be predicted.In order to examine this model efficacy the hindcastings were done.The effectiveness for a given period of time is 5 d.The results shows that the root-mean square error between the predicted and measured of the characteristic temperature was lower than or equal to 0.23℃,the characteristic depth was lower than or equal to 1.18 m and the profile temperature was lower than or equal to 0.20℃.It is shown that the results of trial prediction are satisfactory.
2002, 24(2): 9-19.
Abstract:
The characteristics of surface and upper layer circulation in the Huanghai Sea and East China Sea are discussed by analyzing 142 set of mooring buoy data and trajectories of 58 set of satellite-tracked drifters.The results demonstrate more clearly and directly some main features about the Kuroshio and its branch(to the Tsushima Warm Current),the separation of the Taiwan Warm Current,the Huanghai Sea Warm Current,the Chanjiang diluted water and the eddy developing area.
The characteristics of surface and upper layer circulation in the Huanghai Sea and East China Sea are discussed by analyzing 142 set of mooring buoy data and trajectories of 58 set of satellite-tracked drifters.The results demonstrate more clearly and directly some main features about the Kuroshio and its branch(to the Tsushima Warm Current),the separation of the Taiwan Warm Current,the Huanghai Sea Warm Current,the Chanjiang diluted water and the eddy developing area.
2002, 24(2): 20-29.
Abstract:
In this study,interface waves of thermocline layer are simulated by the model in the Bohai Sea.The waves are excited by tidal oscillation.The numerical model is three-dimensional nonlinear.In the vertical direction,the sea is separated into three layers,namely,upper mixing layer,thermal layer and lower mixing layer.Four principal tidal components,which are M2,S2,K1,O1 are considered in the model.So the surface waves are tidal ones.Not only the temporal varied internal waves have been analyzed,but time-mean values of them,which are called undulation in the paper,have been did.The result shows that the wave of the thermocline is consistent with observations.The waves in the upper and lower surface of thermocline are different in the phase,amplitude,even period in many places.The interface waves of large amplitude occur in the areas with a convex coastline and complex variation of depth.Compared with tidal residual elevation,the undulations of thermocline are larger.And higher absolute values also lie in the near coastline and the areas with complex topography.The bottom friction and topography play a major role for the undulation and interface-wave height.
In this study,interface waves of thermocline layer are simulated by the model in the Bohai Sea.The waves are excited by tidal oscillation.The numerical model is three-dimensional nonlinear.In the vertical direction,the sea is separated into three layers,namely,upper mixing layer,thermal layer and lower mixing layer.Four principal tidal components,which are M2,S2,K1,O1 are considered in the model.So the surface waves are tidal ones.Not only the temporal varied internal waves have been analyzed,but time-mean values of them,which are called undulation in the paper,have been did.The result shows that the wave of the thermocline is consistent with observations.The waves in the upper and lower surface of thermocline are different in the phase,amplitude,even period in many places.The interface waves of large amplitude occur in the areas with a convex coastline and complex variation of depth.Compared with tidal residual elevation,the undulations of thermocline are larger.And higher absolute values also lie in the near coastline and the areas with complex topography.The bottom friction and topography play a major role for the undulation and interface-wave height.
2002, 24(2): 30-38.
Abstract:
Considering the significant contribution of the periodic components to the secular trends of relative sea level(RSL) change,the Fourier transform and the maximum flat filter were applied to eliminate the effects of periodic components on the determination of the secular trends of RSL change.The secular trend of RSL change was determined by linear regression of low-pass series.The empirical orthogonal function(EOF) was used to analyse the characteristics of RSL change; the average rate of water level change in the Zhujiang River Delta was calculated by the main mode of EOF,which is 0.02 mm/a.According to the secular trends of gauge stations in the networks,the response of water level change to the channel degradation and aggradation was discussed.
Considering the significant contribution of the periodic components to the secular trends of relative sea level(RSL) change,the Fourier transform and the maximum flat filter were applied to eliminate the effects of periodic components on the determination of the secular trends of RSL change.The secular trend of RSL change was determined by linear regression of low-pass series.The empirical orthogonal function(EOF) was used to analyse the characteristics of RSL change; the average rate of water level change in the Zhujiang River Delta was calculated by the main mode of EOF,which is 0.02 mm/a.According to the secular trends of gauge stations in the networks,the response of water level change to the channel degradation and aggradation was discussed.
2002, 24(2): 39-50.
Abstract:
The relationship between atmosphere climate basic state and westerly wind anomalies over the equatorial western Pacific is studied by using composite method during 8 El Niño year since 1961.It is found that the western wind anomaly over equatorial western Pacific shows clear seasonal variability similar to that in the atmosphere climate basic state.These characteristics of seasonal variation are successfully simulated with a simple equatorial ocean-atmosphere coupled model.The model results show that the atmosphere basic climate state is very important for generation of western wind anomaly over the equatorial western Pacific.Atmosphere basic climate state effects on the western wind anomaly over the equatorial western Pacific through the heating in the atmosphere model.The effects of SSTA and atmosphere climate basic state on the heating in the atmosphere model vary with the phase of ENSO cycle and geographical location.In the beginning of EN50 cycle,the atmosphere climate basic state plays an important role in forming heating field in the atmosphere model over the equatorial Pacific.During the developing or mature phase of ENSO cycle,the SSTA plays a more important role in forming heating field in the atmosphere model over the mid-eastern equatorial Pacific.Sensitive test of the coupled model to atmosphere climate basic state was made.It shows that the propagating characteristics of westerly wind anomaly along the equatorial Pacific close to the observations.
The relationship between atmosphere climate basic state and westerly wind anomalies over the equatorial western Pacific is studied by using composite method during 8 El Niño year since 1961.It is found that the western wind anomaly over equatorial western Pacific shows clear seasonal variability similar to that in the atmosphere climate basic state.These characteristics of seasonal variation are successfully simulated with a simple equatorial ocean-atmosphere coupled model.The model results show that the atmosphere basic climate state is very important for generation of western wind anomaly over the equatorial western Pacific.Atmosphere basic climate state effects on the western wind anomaly over the equatorial western Pacific through the heating in the atmosphere model.The effects of SSTA and atmosphere climate basic state on the heating in the atmosphere model vary with the phase of ENSO cycle and geographical location.In the beginning of EN50 cycle,the atmosphere climate basic state plays an important role in forming heating field in the atmosphere model over the equatorial Pacific.During the developing or mature phase of ENSO cycle,the SSTA plays a more important role in forming heating field in the atmosphere model over the mid-eastern equatorial Pacific.Sensitive test of the coupled model to atmosphere climate basic state was made.It shows that the propagating characteristics of westerly wind anomaly along the equatorial Pacific close to the observations.
2002, 24(2): 51-58.
Abstract:
According to the Seastar/Sea WiFS remote sensing data and in-situ sediment concentration data acquired quasi-synchronously,the quantitative remote sensing model for suspended sediment in the Changjiang Estuary is set up.The primary Sea WiFS data are geolocated by the "exact closed-form" algorithm,and atmospherically corrected with the simplified procedures for the atmosphere transference computation,so the surface reflectance is got.After these,the remote sensing parameter,which shows the typical spectral features for sediment concentration,is obtained,and is correlated with the in-situ sediment concentration.Finally,the quantitative remote sensing model is got for sediment concentration.
According to the Seastar/Sea WiFS remote sensing data and in-situ sediment concentration data acquired quasi-synchronously,the quantitative remote sensing model for suspended sediment in the Changjiang Estuary is set up.The primary Sea WiFS data are geolocated by the "exact closed-form" algorithm,and atmospherically corrected with the simplified procedures for the atmosphere transference computation,so the surface reflectance is got.After these,the remote sensing parameter,which shows the typical spectral features for sediment concentration,is obtained,and is correlated with the in-situ sediment concentration.Finally,the quantitative remote sensing model is got for sediment concentration.
2002, 24(2): 59-65.
Abstract:
The water quality parameters such as pH,DO,COD,PO4-P,SiO3-Si,NO2-N,NO3-N in the Haikou Bay were monitored respectively before and after No.9618 typhoon occurring on September.18,1996.Based on the statistics of typhoon in the Haikou Bay and numerical calculation of stormy current,the mechanism of water quality variation caused by typhoon was discussed.The studies are as follows:The typhoons influenced on the Haikou Bay usually appear between July and November,most usually between August and October.The monitoring result before typhoon is different from that after typhoon.The stormy wave and windstorm current stir up the sediment in nearshore sea bottom and make bottom water mix with surface eater strongly,specially windstorm current with strong velocity in the top bay stirs up higher pollutants sediment near sea area of discharge ditch,and strong rain with typhoon carries the pollutants from land through the Nandu River to enter into the Haikou Bay,so the contents of COD,PO4-P,N2-N,NO3-N,SiO3-Si after typhoon are higher than those before typhoon.Windstorm current is violent,which made offshore high DO water exchange more frequently with inner bay water and oxygen in the air dissolve in sea water fast,so DO content after typhoon is higher than that before typhoon.This strong action of water exchange also causes pH change small before and after typhoon.
The water quality parameters such as pH,DO,COD,PO4-P,SiO3-Si,NO2-N,NO3-N in the Haikou Bay were monitored respectively before and after No.9618 typhoon occurring on September.18,1996.Based on the statistics of typhoon in the Haikou Bay and numerical calculation of stormy current,the mechanism of water quality variation caused by typhoon was discussed.The studies are as follows:The typhoons influenced on the Haikou Bay usually appear between July and November,most usually between August and October.The monitoring result before typhoon is different from that after typhoon.The stormy wave and windstorm current stir up the sediment in nearshore sea bottom and make bottom water mix with surface eater strongly,specially windstorm current with strong velocity in the top bay stirs up higher pollutants sediment near sea area of discharge ditch,and strong rain with typhoon carries the pollutants from land through the Nandu River to enter into the Haikou Bay,so the contents of COD,PO4-P,N2-N,NO3-N,SiO3-Si after typhoon are higher than those before typhoon.Windstorm current is violent,which made offshore high DO water exchange more frequently with inner bay water and oxygen in the air dissolve in sea water fast,so DO content after typhoon is higher than that before typhoon.This strong action of water exchange also causes pH change small before and after typhoon.
2002, 24(2): 66-76.
Abstract:
The daily variations of Chl.a,POC,primary production and 234Th/238U disequilibria in the Xiamen Bay were studied.POC concentration in the study area ranged from 14.4 to 34.6 mmol/m3,with an average concentration of 21.6 mmol/m3.The contributions of living organic carbon(phytoplankton) and organic detritus were estimated to be about 8%-26% and 74%-92% of the total POC,respectively.The profiles of POC showed a gradually decrease with the depth,and its temporal variation showed that the POC concentrations in daytime are higher than those in nighttime.Both features suggested that POC is closely related to biological processes in the Xiamen Bay.The primary production in the study area varied up to 5-folds in 1 d,which was consistent with that of the biomass.Primary production also decreased with the depth,was coincident with the patterns of Chl.a and POC.In the meantime,we studied the effect of incubation time on the determination of primary production.The primary production calculated from short-time incubation(2 h) is higher than that from long-time incubation(24 h),indicating some of the new fixed carbon are preferentially respired and then excreted.Based on the particulate 234Th export fluxes from 234Th/238U disequilibria and the POC/PTh,ratios in particles,the Pox-export flux from euphotic zone is estimated to be 16.0 mmol/(m2·d),in which the export fluxes of living organic carbon and detrital organic carbon are 2.7 and 13,3 mmol(m2·d),respectively.The ratio between POC export flux and primary production,referred as ThE ratio,is 0.31.Both POC export fluxes and ThE ratios are consistent with the prediction value from relation formula presented by Aksnes and Wassmann in 1993,but not with other models.The residence time of POC in the euphotic zone was estimated to be 11 d,indicating a rapid regeneration rate of POC in study sea area.
The daily variations of Chl.a,POC,primary production and 234Th/238U disequilibria in the Xiamen Bay were studied.POC concentration in the study area ranged from 14.4 to 34.6 mmol/m3,with an average concentration of 21.6 mmol/m3.The contributions of living organic carbon(phytoplankton) and organic detritus were estimated to be about 8%-26% and 74%-92% of the total POC,respectively.The profiles of POC showed a gradually decrease with the depth,and its temporal variation showed that the POC concentrations in daytime are higher than those in nighttime.Both features suggested that POC is closely related to biological processes in the Xiamen Bay.The primary production in the study area varied up to 5-folds in 1 d,which was consistent with that of the biomass.Primary production also decreased with the depth,was coincident with the patterns of Chl.a and POC.In the meantime,we studied the effect of incubation time on the determination of primary production.The primary production calculated from short-time incubation(2 h) is higher than that from long-time incubation(24 h),indicating some of the new fixed carbon are preferentially respired and then excreted.Based on the particulate 234Th export fluxes from 234Th/238U disequilibria and the POC/PTh,ratios in particles,the Pox-export flux from euphotic zone is estimated to be 16.0 mmol/(m2·d),in which the export fluxes of living organic carbon and detrital organic carbon are 2.7 and 13,3 mmol(m2·d),respectively.The ratio between POC export flux and primary production,referred as ThE ratio,is 0.31.Both POC export fluxes and ThE ratios are consistent with the prediction value from relation formula presented by Aksnes and Wassmann in 1993,but not with other models.The residence time of POC in the euphotic zone was estimated to be 11 d,indicating a rapid regeneration rate of POC in study sea area.
2002, 24(2): 77-83.
Abstract:
The Holocene sea-level rise of the Nile Delta is reconstructed on the basis of radiocarbon dates that are derived from 33 peat samples and 65 lagoon samples obtained from many boreholes located in the lower delta plain.The result indicates that the lagoonal curve is more reliable than that of the peat curve,the latter is much influenced by the sediment compact.The result also shows that the sea level was about 10 m below the present during 7 000 a B.P.,about 5 m below the present in 5 000 a B.P.,and was nearer to the present in 2 000 a B.P.Affected by the paleotopography and regional subsidence of the study area,the largest impact from transgressive intensity and scope tends to occur in the northeastern Nile sector.This influence becomes progressively reduced toward the central and northwestern Nile sectors.A vast Nile Delta Plain dominated by lagoon-sand beach and fluvial plain system had began to build at about 7 000 a B.P.,when rise in sea level started to decelerate and deltaic sedimentation rate overwhelmed the sea contribution.As sea level tends to be stabilized in Late Holocene,human activity,such as reclamation and channelisation,induces environmental deterioration,represented by largely shrunken lagoonal system.A comparable example of the Changjiang Delta is cited in the present study.It is shown that the Holocene Changjiang sea level did not fluctuate coincidentally as the Nile,much likely due to the differences of regional subsidence between the two regions.The fertile delta plain that was formed by the delta-coast construction at about 7 000 a B.P.induced the Neolithic civilization.However,intensifying human activity since 2000 a B.P.also has aggravated the delta-coast environment.Many lakes and drainage networks are diminishing.
The Holocene sea-level rise of the Nile Delta is reconstructed on the basis of radiocarbon dates that are derived from 33 peat samples and 65 lagoon samples obtained from many boreholes located in the lower delta plain.The result indicates that the lagoonal curve is more reliable than that of the peat curve,the latter is much influenced by the sediment compact.The result also shows that the sea level was about 10 m below the present during 7 000 a B.P.,about 5 m below the present in 5 000 a B.P.,and was nearer to the present in 2 000 a B.P.Affected by the paleotopography and regional subsidence of the study area,the largest impact from transgressive intensity and scope tends to occur in the northeastern Nile sector.This influence becomes progressively reduced toward the central and northwestern Nile sectors.A vast Nile Delta Plain dominated by lagoon-sand beach and fluvial plain system had began to build at about 7 000 a B.P.,when rise in sea level started to decelerate and deltaic sedimentation rate overwhelmed the sea contribution.As sea level tends to be stabilized in Late Holocene,human activity,such as reclamation and channelisation,induces environmental deterioration,represented by largely shrunken lagoonal system.A comparable example of the Changjiang Delta is cited in the present study.It is shown that the Holocene Changjiang sea level did not fluctuate coincidentally as the Nile,much likely due to the differences of regional subsidence between the two regions.The fertile delta plain that was formed by the delta-coast construction at about 7 000 a B.P.induced the Neolithic civilization.However,intensifying human activity since 2000 a B.P.also has aggravated the delta-coast environment.Many lakes and drainage networks are diminishing.
2002, 24(2): 84-93.
Abstract:
Supported by GIS,10 pieces of charts of the Changjiang Estuary from 1842 to 1997 are studied.Digital elevation model of the Changjiang Estuary is established with Kriging gridding method to research evolution of channel,change of coasts,formation and evolution of islands in mouth bar area with different points of view:transverse sections,longitudinal profiles,plane change,etc.Furthermore channel-fill volumes are calculated and calculations of amount of deposition and erosion in different scopes between different years are conducted.The calculated results show that the evolution of mouth bar area of the Changjiang Estuary was complex in near 155 a(1842-1997):deposition has its trend,but the speeds of deposition in different terms are different and erosion occurs place in a few terms which mainly are related to dynamic conditions.About 3.81 Gt of sediment was deposited between 1842 and 1997,with average annual deposition rate of 24.6 Mt which amounts to 5% of sediment form the Changjiang River.Jiuduansha,Hengsha and its east beach,and east beach of Chongming Island are the main positions of siltation and the current North Passage is the main position of erosion.In addition,there is slight erosion in the upper part of the North Channel and part of the South Passage.Together,the area of erosion is limited and it only amounts to 21.496 of total study area.
Supported by GIS,10 pieces of charts of the Changjiang Estuary from 1842 to 1997 are studied.Digital elevation model of the Changjiang Estuary is established with Kriging gridding method to research evolution of channel,change of coasts,formation and evolution of islands in mouth bar area with different points of view:transverse sections,longitudinal profiles,plane change,etc.Furthermore channel-fill volumes are calculated and calculations of amount of deposition and erosion in different scopes between different years are conducted.The calculated results show that the evolution of mouth bar area of the Changjiang Estuary was complex in near 155 a(1842-1997):deposition has its trend,but the speeds of deposition in different terms are different and erosion occurs place in a few terms which mainly are related to dynamic conditions.About 3.81 Gt of sediment was deposited between 1842 and 1997,with average annual deposition rate of 24.6 Mt which amounts to 5% of sediment form the Changjiang River.Jiuduansha,Hengsha and its east beach,and east beach of Chongming Island are the main positions of siltation and the current North Passage is the main position of erosion.In addition,there is slight erosion in the upper part of the North Channel and part of the South Passage.Together,the area of erosion is limited and it only amounts to 21.496 of total study area.
2002, 24(2): 94-100.
Abstract:
A micro-structural theory and a technical method of Quaternary geology are used to study engineering geological estimating problems of sediments in off-sea of the Zhujiang River mouth.Soft soil structures,microstructure and classification characteristics are analysed by using method of electron microscope.On the basis of analysing physical-mechanical characteristic parameters,the relation among grain contact,grain accumultion and porosity with physical-mechanical characteristics of sediments are studied.The study result shows that there are 6 micro-structural types in sediments of off-sea of the Zhujiang River mouth,and among these,the mixed contact structural sediment has higher compressive strength than others.
A micro-structural theory and a technical method of Quaternary geology are used to study engineering geological estimating problems of sediments in off-sea of the Zhujiang River mouth.Soft soil structures,microstructure and classification characteristics are analysed by using method of electron microscope.On the basis of analysing physical-mechanical characteristic parameters,the relation among grain contact,grain accumultion and porosity with physical-mechanical characteristics of sediments are studied.The study result shows that there are 6 micro-structural types in sediments of off-sea of the Zhujiang River mouth,and among these,the mixed contact structural sediment has higher compressive strength than others.
2002, 24(2): 101-106.
Abstract:
The detected results of the heterotrophic bacteria in the sea water samples,sediment fsamples and shellfish samples collected from six seacoast areas in the Bohai Sea and the Huanghai Sea(Lüsi,Qingdao,Beidaihe,Panjin,Dalian and Zhuanghe) are reported.The research results show that the average amount of the heterotrophic bacteria is 2.7×105 cfu/g,ranging from 2.0×103 to 1.6×106 cfu/g in the shellfish samples;1.2×107 cfu/dm3,ranging from 2.5×105 to 1.0×108 cuf/dm3 in sea water samples;1.3×105 cfu/g,ranging from 2.8×103 to 7.5 ×105 cuf/g.
The detected results of the heterotrophic bacteria in the sea water samples,sediment fsamples and shellfish samples collected from six seacoast areas in the Bohai Sea and the Huanghai Sea(Lüsi,Qingdao,Beidaihe,Panjin,Dalian and Zhuanghe) are reported.The research results show that the average amount of the heterotrophic bacteria is 2.7×105 cfu/g,ranging from 2.0×103 to 1.6×106 cfu/g in the shellfish samples;1.2×107 cfu/dm3,ranging from 2.5×105 to 1.0×108 cuf/dm3 in sea water samples;1.3×105 cfu/g,ranging from 2.8×103 to 7.5 ×105 cuf/g.
2002, 24(2): 107-113.
Abstract:
The genetic diversity of four reared populations(Dalijiadipai DLJD,Dalijiagaopai DLJG,Lingshuiqiao LSQ,Qipanmo QPM) of bay scallop Argopecten irradians(Lamarck) at the coastal shellfish farms in Dalian had been investigated based on polyacrylamide gel electrophoresis for allozyme.22 loci in 7 enzymes and general protein were detected.Based on the 22 common loci of samples in four populations,the proportion of polymorphic loci was 22.73%,22.73%,22.73% and 18.18% respectively under the criterion P≤0.95 and 27.27%,27.27%,31.82% and 36.36% respectively under the criterion P≤0.99; the mean heterozygosity observed was 0.064,0.071,0.075 and 0.069 respectively; the deviation index from Hardy-Weinberg equilibrium was-0.068,-0.020,-0.032 and-0.050 respectively; inbreeding coefficient was 0.568,0.565,0.487 and 0.550 respectively; the mean effective number of allele in a locus was 1.102,1.109,1.143 and 1.122 respectively; the comprehensive index of genetic variation was 0.006 0,0.007 1,0.008 8 and 0.007 3 respectively.The genetic diversity of the bay scallop was lower than the average of bivalve.The genetic diversity in LSQ was the highest,in DLJG and QPM was higher,in DLJD was the lowest among the four populations.
The genetic diversity of four reared populations(Dalijiadipai DLJD,Dalijiagaopai DLJG,Lingshuiqiao LSQ,Qipanmo QPM) of bay scallop Argopecten irradians(Lamarck) at the coastal shellfish farms in Dalian had been investigated based on polyacrylamide gel electrophoresis for allozyme.22 loci in 7 enzymes and general protein were detected.Based on the 22 common loci of samples in four populations,the proportion of polymorphic loci was 22.73%,22.73%,22.73% and 18.18% respectively under the criterion P≤0.95 and 27.27%,27.27%,31.82% and 36.36% respectively under the criterion P≤0.99; the mean heterozygosity observed was 0.064,0.071,0.075 and 0.069 respectively; the deviation index from Hardy-Weinberg equilibrium was-0.068,-0.020,-0.032 and-0.050 respectively; inbreeding coefficient was 0.568,0.565,0.487 and 0.550 respectively; the mean effective number of allele in a locus was 1.102,1.109,1.143 and 1.122 respectively; the comprehensive index of genetic variation was 0.006 0,0.007 1,0.008 8 and 0.007 3 respectively.The genetic diversity of the bay scallop was lower than the average of bivalve.The genetic diversity in LSQ was the highest,in DLJG and QPM was higher,in DLJD was the lowest among the four populations.
2002, 24(2): 114-120.
Abstract:
Three-factors experiment design is used to study the combined effects of temperature,salinity and irradiance on the growth of an important PSP(paralytic shellfish poisoning) producing species A.tamarense(a strain isolated from the Daya Bay,Uuangdong,China).The results show that growth of A.tamarense is significantly different among temperatures(12,19,25,32℃),irradiance(0.02×1016,0.08×1016,0.3×1016,1.6×1016 s-1/cm2) and salinity(10,18,25,30,35).There are interactive effects between any two of and among all three physical factors on the growth of A.tamarense.The optimal growth condition of A.tamarense is 19℃,30 and 1.6×1016s-1/cm2 with growth rate of 0.25d during exponential growth phase.Therefore,A.tamarense is more likely to bloom under relatively high temperature and high illumination in spring and autumn,and this species is able to grow in ocean area of relatively high salinity.Red tide formation mechanism and possible distribution of this species in China are also discussed.To protect mariculture industry and human health,more attention should be paid to this toxic species.
Three-factors experiment design is used to study the combined effects of temperature,salinity and irradiance on the growth of an important PSP(paralytic shellfish poisoning) producing species A.tamarense(a strain isolated from the Daya Bay,Uuangdong,China).The results show that growth of A.tamarense is significantly different among temperatures(12,19,25,32℃),irradiance(0.02×1016,0.08×1016,0.3×1016,1.6×1016 s-1/cm2) and salinity(10,18,25,30,35).There are interactive effects between any two of and among all three physical factors on the growth of A.tamarense.The optimal growth condition of A.tamarense is 19℃,30 and 1.6×1016s-1/cm2 with growth rate of 0.25d during exponential growth phase.Therefore,A.tamarense is more likely to bloom under relatively high temperature and high illumination in spring and autumn,and this species is able to grow in ocean area of relatively high salinity.Red tide formation mechanism and possible distribution of this species in China are also discussed.To protect mariculture industry and human health,more attention should be paid to this toxic species.
2002, 24(2): 121-126.
Abstract:
A practical model for the simulation of wave set-up in coastal areas is proposed.The variation of the complex wave amplitude is numerically simulated first by use of the parabolic mild-slope equation including the effect of the wave energy dissipation due to wave breaking.The components of wave radiation stress are calculated subsequently by new expressions for them according to the obtained complex wave amplitude,and then the depthaveraged equation is applied to the calculation of wave set-up due to wave breaking.The model is used to simulate the wave set-up of regular and irregular waves.The numerical results are in good agreement with experimental data,which shows that the model can simulate effectively the wave set-up due to wave breaking in the coastal areas.
A practical model for the simulation of wave set-up in coastal areas is proposed.The variation of the complex wave amplitude is numerically simulated first by use of the parabolic mild-slope equation including the effect of the wave energy dissipation due to wave breaking.The components of wave radiation stress are calculated subsequently by new expressions for them according to the obtained complex wave amplitude,and then the depthaveraged equation is applied to the calculation of wave set-up due to wave breaking.The model is used to simulate the wave set-up of regular and irregular waves.The numerical results are in good agreement with experimental data,which shows that the model can simulate effectively the wave set-up due to wave breaking in the coastal areas.
2002, 24(2): 127-132.
Abstract:
MAC(marker and cell) method is applied to solve the N-S equation and continuity equation numerically.In order to simulate successive long-time wave generation of irregular waves and absorb the reflected waves from a structure,the source generation of waves is applied.A sponge layer for wave damping absorber combined with the Sommerfeld radiation is used to the open boundary.
MAC(marker and cell) method is applied to solve the N-S equation and continuity equation numerically.In order to simulate successive long-time wave generation of irregular waves and absorb the reflected waves from a structure,the source generation of waves is applied.A sponge layer for wave damping absorber combined with the Sommerfeld radiation is used to the open boundary.
2002, 24(2): 133-139.
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2002, 24(2): 140-145.
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2002, 24(2): 146-148.
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