2009 Vol. 31, No. 3
Display Method:
2009, 31(3): 1-11.
Abstract:
The variability of equatorial undercurrent in tropical Pacific and its relationship with ENSO cycle were analyzed using velocity data from Tropical Ocean and Global Atmosphere-Tropical Atmosphere Ocean array and Simple Ocean Data Assimilation dataset.The influence of equatorial undercurrent on different pattern ENSO events(eastern pattern and central pattern) was tentatively discussed.The result of Empirical Orthogonal Function(EOF) analysis for the anomaly of equat orial under current showed that the characteristic vect or of first mode mainly reflected the variability of Eastern Pacific equatorial undercurrent and the second mode mainly reflected the variability of Central Pacific equatorial undercurrent.These two main modes could show the basic variability of equatorial undercurrent in the Pacific Ocean.The time coefficients of the two modes have obvious interannual variability and they have obvious negative correlations with the NINO index.It revealed that the inf luence of EN SO cycle on the equato rialunder current was shown mainly by the variability of Eastern Pacific under current.And the equatorial undercurrent affected the ENSO events by the variability of Central Pacific undercurrent.The variation of under current in the central pacific has important influence on the different pattern ENSO events.In the ENSO cycle,when the equatorial undercurrent sing ularly increased in central Pacific,the anomalous temperature in western Pacific subsurface propagated to the east and the SSTA reached eastern Pacific,so the eastern pattern ENSO events occurred.Contrarily when the equatorial undercurrent decreased in central Pacific,the anomalous seawater gathered in central Pacific making the sea surface temperature anomaly in central Pacific first,so the central pattern ENSO events occurred.
The variability of equatorial undercurrent in tropical Pacific and its relationship with ENSO cycle were analyzed using velocity data from Tropical Ocean and Global Atmosphere-Tropical Atmosphere Ocean array and Simple Ocean Data Assimilation dataset.The influence of equatorial undercurrent on different pattern ENSO events(eastern pattern and central pattern) was tentatively discussed.The result of Empirical Orthogonal Function(EOF) analysis for the anomaly of equat orial under current showed that the characteristic vect or of first mode mainly reflected the variability of Eastern Pacific equatorial undercurrent and the second mode mainly reflected the variability of Central Pacific equatorial undercurrent.These two main modes could show the basic variability of equatorial undercurrent in the Pacific Ocean.The time coefficients of the two modes have obvious interannual variability and they have obvious negative correlations with the NINO index.It revealed that the inf luence of EN SO cycle on the equato rialunder current was shown mainly by the variability of Eastern Pacific under current.And the equatorial undercurrent affected the ENSO events by the variability of Central Pacific undercurrent.The variation of under current in the central pacific has important influence on the different pattern ENSO events.In the ENSO cycle,when the equatorial undercurrent sing ularly increased in central Pacific,the anomalous temperature in western Pacific subsurface propagated to the east and the SSTA reached eastern Pacific,so the eastern pattern ENSO events occurred.Contrarily when the equatorial undercurrent decreased in central Pacific,the anomalous seawater gathered in central Pacific making the sea surface temperature anomaly in central Pacific first,so the central pattern ENSO events occurred.
2009, 31(3): 12-20.
Abstract:
Emulsificated oil and decomposed oil in water can be absorbed by suspended particles and influence the scattering properties of the particles.Backscattering coefficient is one of the important parameters on ocean color sensing and a key factor to the establishment of semianaly tical model,so as to the retrieval of petroleum pollution concentrations.The field data were collected in the rivers in Panjin City,Liaoning Province,China in May 2008,including absor ption coefficients of yellow subst ance,de-pig mented particles and phyt oplankt on pig ments.The backscattering data were measured by the in-situ spectral backscattering sensor,Hydro Scat-6.Water samples for chlorophyll and sediment concent rations as well as petroleum contamination were also collected.Based on the analysis of inherent optical properties,two models were established.One is the spectral model of water backscattering coefficient with petroleum pollution,and another is the relationship between the water backscattering coefficient and the inorganic particle concentration,including two types of water,with and without petroleum pollution.The results show that(1) the averaging exponent is 0.87 fo rall spectral backscattering models;(2) according to the correlative coefficients between the backscattering coefficient with phytoplankt on,inorganic particles,and petroleum pollution,the inorganic particles have a dominant effect on the water backscat tering,petroleum pollution is the next,and phy to plankt on almost has not any effect,since the sedimentload is higher than 100 mg/m3;and(3) in the waters without petroleum pollution,the relationship between sediment concentration and back-scattering coefficient is well formulated by logarithm function,however,in the waters with petroleum pollution,the linear relation is more suitable.
Emulsificated oil and decomposed oil in water can be absorbed by suspended particles and influence the scattering properties of the particles.Backscattering coefficient is one of the important parameters on ocean color sensing and a key factor to the establishment of semianaly tical model,so as to the retrieval of petroleum pollution concentrations.The field data were collected in the rivers in Panjin City,Liaoning Province,China in May 2008,including absor ption coefficients of yellow subst ance,de-pig mented particles and phyt oplankt on pig ments.The backscattering data were measured by the in-situ spectral backscattering sensor,Hydro Scat-6.Water samples for chlorophyll and sediment concent rations as well as petroleum contamination were also collected.Based on the analysis of inherent optical properties,two models were established.One is the spectral model of water backscattering coefficient with petroleum pollution,and another is the relationship between the water backscattering coefficient and the inorganic particle concentration,including two types of water,with and without petroleum pollution.The results show that(1) the averaging exponent is 0.87 fo rall spectral backscattering models;(2) according to the correlative coefficients between the backscattering coefficient with phytoplankt on,inorganic particles,and petroleum pollution,the inorganic particles have a dominant effect on the water backscat tering,petroleum pollution is the next,and phy to plankt on almost has not any effect,since the sedimentload is higher than 100 mg/m3;and(3) in the waters without petroleum pollution,the relationship between sediment concentration and back-scattering coefficient is well formulated by logarithm function,however,in the waters with petroleum pollution,the linear relation is more suitable.
2009, 31(3): 21-29.
Abstract:
An attenuation depth is defined for remote sensing purposes as adepth above which 90% of the arising light leaving the water surface is emanated.The deeper the attenuation depth,the more information of water is detected by remote sensing,then the more precise information of water is extracted.Mean-while,the attenuation depth is help to know water layer(by it s thickness) from which remote sensing will be able to extract information.A number of investigators are using the moderate resolut ion imaging spectroradiometer(or MODIS) for remote sensing of ocean color.It is necessary to have a rough idea of the effectiveat tenuation depth of imagery in each of the spectral bands employed by the MODIS.The attenuation depth is directly determined from MODIS data.Though analyzing the spectral distributions of attenuation depth on 7 August 2003 and the seasonal variations of attenuation depth(551nm) in the Bohai Sea indicated that the spectral distributions of the attenuation depth for the spectralrange 400~700 nm are single-peak curves,and their similar and difference in different regions consist with other scholarsc results of zoning,moreover their support the Bohai Sea is Case 2 water;the maximum at tenuation depths shift to-ward longer wavelengths,liking thered shift,with increase of turbidity of water,just like in these regions representing by Points C and G is at 531nm,by Point Fis the maximum attenuation depth at 551nm,by Points A,B,D and E is at 555nm;the seasonal change of the attenuation depth is the largest in the summer,followed by the fall,and the ranking of winter and spring in different regions is varied.The at tenuation depth in different regions is varied:the attenuation depth of Points A and E is less than that of Point Dless than that of Pint Bless than that of Points C and F less than that of point G(excluding 412 and 645nm) ,in which the order of at tenuation depth of between Points A and E(and between Points F and C) representing regions is dissimilarity in different seasons and different bands.
An attenuation depth is defined for remote sensing purposes as adepth above which 90% of the arising light leaving the water surface is emanated.The deeper the attenuation depth,the more information of water is detected by remote sensing,then the more precise information of water is extracted.Mean-while,the attenuation depth is help to know water layer(by it s thickness) from which remote sensing will be able to extract information.A number of investigators are using the moderate resolut ion imaging spectroradiometer(or MODIS) for remote sensing of ocean color.It is necessary to have a rough idea of the effectiveat tenuation depth of imagery in each of the spectral bands employed by the MODIS.The attenuation depth is directly determined from MODIS data.Though analyzing the spectral distributions of attenuation depth on 7 August 2003 and the seasonal variations of attenuation depth(551nm) in the Bohai Sea indicated that the spectral distributions of the attenuation depth for the spectralrange 400~700 nm are single-peak curves,and their similar and difference in different regions consist with other scholarsc results of zoning,moreover their support the Bohai Sea is Case 2 water;the maximum at tenuation depths shift to-ward longer wavelengths,liking thered shift,with increase of turbidity of water,just like in these regions representing by Points C and G is at 531nm,by Point Fis the maximum attenuation depth at 551nm,by Points A,B,D and E is at 555nm;the seasonal change of the attenuation depth is the largest in the summer,followed by the fall,and the ranking of winter and spring in different regions is varied.The at tenuation depth in different regions is varied:the attenuation depth of Points A and E is less than that of Point Dless than that of Pint Bless than that of Points C and F less than that of point G(excluding 412 and 645nm) ,in which the order of at tenuation depth of between Points A and E(and between Points F and C) representing regions is dissimilarity in different seasons and different bands.
2009, 31(3): 30-38.
Abstract:
The Changjiang Estuary is located in the East China Sea shelf with shallow water1 Affected by the tide mixing and the runoff of the Chang jiang River and the Qiantang River,the turbidity is very high. Generally,the water-leaving radiance is high in the turbid water with particle scattering. On the basis of the in-situ data and the ocean color remote sensing data of SeaWiFS,it was found that there was a black water region with thenorm alized water-leaving radiances less than 0.5 mW/(cm2·μm·sr) . The optical principle of the occurrence of this black water was analyzed with the inherentoptical properties and the ocean color components. The results show that the black water was caused by the relative low values of the suspended particlematter content and the back scatteringratio. In the black water region,the percentage of the phytoplankt on absorption was relative high,and the large radius of the phytoplankton particle caused the low value of the back scatteringration.
The Changjiang Estuary is located in the East China Sea shelf with shallow water1 Affected by the tide mixing and the runoff of the Chang jiang River and the Qiantang River,the turbidity is very high. Generally,the water-leaving radiance is high in the turbid water with particle scattering. On the basis of the in-situ data and the ocean color remote sensing data of SeaWiFS,it was found that there was a black water region with thenorm alized water-leaving radiances less than 0.5 mW/(cm2·μm·sr) . The optical principle of the occurrence of this black water was analyzed with the inherentoptical properties and the ocean color components. The results show that the black water was caused by the relative low values of the suspended particlematter content and the back scatteringratio. In the black water region,the percentage of the phytoplankt on absorption was relative high,and the large radius of the phytoplankton particle caused the low value of the back scatteringration.
2009, 31(3): 39-45.
Abstract:
The variation of underwater bathymetry in the radial sand ridge group of the southern Huanghai Sea is complex and changeable owing to abundant sediment supply of different sources and varied hydrodynamic processes. Remote sensing has potential and is imperative for the surveying and monitoring variation of under water topography with quick and largearea data acquisition abilities. So based on the experiences of water depth in the Changjiang Estuary and coastal area with the remote sensing rever sion,a typicalregion in radial sand ridge was chosen for bat hymetry reversion viaremo tesensing technology. Tidal current and content of suspended sediments were surveyed synchronously during the measurement of water depth. Spectral characteristics of suspended sediments were analyzed and a spectrum based on sedimentrever sion parameter was obtained to reduce its influence on water depth information contained in MODIS image. And then real observed bathymetry data were used to establish a remote sensing rever sion model. The under water to pography of about 1.5×104km2 in the radial sand ridge group region was then acquired with a fairly good precision. The correlation coefficient square between the reversed water depth and the measured reached 0.664. The mean absolute error was approximately 1.52m and the mean relative error was about 24%. The best reversion results appearat water depth range of 5 to 15m. The mean relative error was only 18%. It is indicated that this remote sensing based on the rever sion technology was suitable for the under water bathy metry reversion in a complex coastal area especially with a relatively shallow water depth.
The variation of underwater bathymetry in the radial sand ridge group of the southern Huanghai Sea is complex and changeable owing to abundant sediment supply of different sources and varied hydrodynamic processes. Remote sensing has potential and is imperative for the surveying and monitoring variation of under water topography with quick and largearea data acquisition abilities. So based on the experiences of water depth in the Changjiang Estuary and coastal area with the remote sensing rever sion,a typicalregion in radial sand ridge was chosen for bat hymetry reversion viaremo tesensing technology. Tidal current and content of suspended sediments were surveyed synchronously during the measurement of water depth. Spectral characteristics of suspended sediments were analyzed and a spectrum based on sedimentrever sion parameter was obtained to reduce its influence on water depth information contained in MODIS image. And then real observed bathymetry data were used to establish a remote sensing rever sion model. The under water to pography of about 1.5×104km2 in the radial sand ridge group region was then acquired with a fairly good precision. The correlation coefficient square between the reversed water depth and the measured reached 0.664. The mean absolute error was approximately 1.52m and the mean relative error was about 24%. The best reversion results appearat water depth range of 5 to 15m. The mean relative error was only 18%. It is indicated that this remote sensing based on the rever sion technology was suitable for the under water bathy metry reversion in a complex coastal area especially with a relatively shallow water depth.
2009, 31(3): 46-56.
Abstract:
The study of effect to the ocean color environment caused by typhoon is another application of satellite ocean remote sensing.There are less remote sensing data in the period of hurricanes,so many scholars in the world mainly study some specialty phoons' effects on the sea surface temperature(SST) , chloro phyll-a(chl-a) and the primary product and there are fewer people to carry through quant it ativea nalysis and modeling to the effects by remote sensing data. From 2000 to 2007,there were nearly 100 times ty phoons passing through China sea area and the north west Pacific Ocean. By analysing the level "3A" data of chlorophyll-a of the MODIS and SeaWiFS,the authos get some conclusions as follows. first,the chlorophyll-a concent ration in the correlative area has increased,it averagely rises to about 1.426 times than the usual,even over 5 times in several areas. This growing up lagged about 3~6 d and it came back to the normal value after 7~10 d.Second,by using statistic linear regression to the rate of chl-a concent ration increment(Rchl-a) and typhoon-effectfactor(Tsub>w) ,the authors get anequation as follows:Rchl-a=0.0012Tsub>w+1.017 and the correlation coefficient is 0.8.Thirdly,the concent ration(Cchl-a) of chl-a with typhoon and without typhoon has a strong linear relation,which meets such equation as Cchl-a=1.2367C0chl-a+0.0636,and the correlation coefficient is up to 0.98.It is helpful to deeply under stand the effectsof the ocean color environment by the typhoon using remote sensing.
The study of effect to the ocean color environment caused by typhoon is another application of satellite ocean remote sensing.There are less remote sensing data in the period of hurricanes,so many scholars in the world mainly study some specialty phoons' effects on the sea surface temperature(SST) , chloro phyll-a(chl-a) and the primary product and there are fewer people to carry through quant it ativea nalysis and modeling to the effects by remote sensing data. From 2000 to 2007,there were nearly 100 times ty phoons passing through China sea area and the north west Pacific Ocean. By analysing the level "3A" data of chlorophyll-a of the MODIS and SeaWiFS,the authos get some conclusions as follows. first,the chlorophyll-a concent ration in the correlative area has increased,it averagely rises to about 1.426 times than the usual,even over 5 times in several areas. This growing up lagged about 3~6 d and it came back to the normal value after 7~10 d.Second,by using statistic linear regression to the rate of chl-a concent ration increment(Rchl-a) and typhoon-effectfactor(Tsub>w) ,the authors get anequation as follows:Rchl-a=0.0012Tsub>w+1.017 and the correlation coefficient is 0.8.Thirdly,the concent ration(Cchl-a) of chl-a with typhoon and without typhoon has a strong linear relation,which meets such equation as Cchl-a=1.2367C0chl-a+0.0636,and the correlation coefficient is up to 0.98.It is helpful to deeply under stand the effectsof the ocean color environment by the typhoon using remote sensing.
2009, 31(3): 57-66.
Abstract:
Among totally 242 spectral bands ranging from 400 to 2 500 nm of Hyperion hyperspectral remote sensing data,it was found that two bands with reflect ance of 1 215 and 2 133 nm had relatively good correlation with the sediment grain-size parameters of mean diameter,skew ness,medium diameter and sorting coefficient.And further more,the combination of the sum of these two bands divided by their difference had a significant linear correlation with the mean diameter,skew ness and medium diameter while the sorting coefficient had a notable linear relationship with the discr epancy of the mean diameter and medium diameter.On the basis of these relation ships,four linear regression models were established and applied to getting the spatial distribution characteristics of grain-size parameters at the southern part of intertidalflat near the Sheyang Estuary in Jiangsu Province,China.Verification by independent samples show that the mean relative precision and the mean absolute precision exceed 75.70%and 72.17%,respectively. The spatial distribution pattern of grain-sizes indicates that in the direction from north to south that parallel to the coastal line,the grain-size diameters become finer,the sorting charact eristics become worse and the distribution of skew ness moves from near symmetry to positive deviation.While at the direction from land phase to sea that perpendicular to the coastal line,the grain-size diameters change coarser,the sorting character istics become better and the distribution of the skew ness moves from positive to near symmetry. But near the medium tidal level area,sediment is the mixture of fine and coarse matter and the mean diameter is a litter larger than near by part.sorting charact eristic becomes worse from medium to either land or sea direction.These variation trends are in accordance with hydrodynamic enviro nments and sources of sediments well.
Among totally 242 spectral bands ranging from 400 to 2 500 nm of Hyperion hyperspectral remote sensing data,it was found that two bands with reflect ance of 1 215 and 2 133 nm had relatively good correlation with the sediment grain-size parameters of mean diameter,skew ness,medium diameter and sorting coefficient.And further more,the combination of the sum of these two bands divided by their difference had a significant linear correlation with the mean diameter,skew ness and medium diameter while the sorting coefficient had a notable linear relationship with the discr epancy of the mean diameter and medium diameter.On the basis of these relation ships,four linear regression models were established and applied to getting the spatial distribution characteristics of grain-size parameters at the southern part of intertidalflat near the Sheyang Estuary in Jiangsu Province,China.Verification by independent samples show that the mean relative precision and the mean absolute precision exceed 75.70%and 72.17%,respectively. The spatial distribution pattern of grain-sizes indicates that in the direction from north to south that parallel to the coastal line,the grain-size diameters become finer,the sorting charact eristics become worse and the distribution of skew ness moves from near symmetry to positive deviation.While at the direction from land phase to sea that perpendicular to the coastal line,the grain-size diameters change coarser,the sorting character istics become better and the distribution of the skew ness moves from positive to near symmetry. But near the medium tidal level area,sediment is the mixture of fine and coarse matter and the mean diameter is a litter larger than near by part.sorting charact eristic becomes worse from medium to either land or sea direction.These variation trends are in accordance with hydrodynamic enviro nments and sources of sediments well.
2009, 31(3): 67-72.
Abstract:
The Gulf of Mexico is a sea area of deeper study on gas hydrate in the world,plenty of data,and gas hydrate samples have been collected at more than 50 locations,so it possesses the condition to est ablish mineral resource prediction model about gas hydrate 34 known ore occur rences and 34 non ore occurrences were selected as a training area,and the prediction model of ore occurrence existence probability was established. Correlation coefficients indicate that gas hydrate in the Gulf of Mexico has close relation to basin and salt diapir Such model was used in the whole northern Gulf of Mexico and probability figures of gas hydrate distribution were gained;the prediction cell with probabilities greater than 0.5 contains 31 of known ore occurr ences,and this probability value was used to delineate potential resource dist ribution area of gas hydrate in the Gulf of Mexico
The Gulf of Mexico is a sea area of deeper study on gas hydrate in the world,plenty of data,and gas hydrate samples have been collected at more than 50 locations,so it possesses the condition to est ablish mineral resource prediction model about gas hydrate 34 known ore occur rences and 34 non ore occurrences were selected as a training area,and the prediction model of ore occurrence existence probability was established. Correlation coefficients indicate that gas hydrate in the Gulf of Mexico has close relation to basin and salt diapir Such model was used in the whole northern Gulf of Mexico and probability figures of gas hydrate distribution were gained;the prediction cell with probabilities greater than 0.5 contains 31 of known ore occurr ences,and this probability value was used to delineate potential resource dist ribution area of gas hydrate in the Gulf of Mexico
2009, 31(3): 73-83.
Abstract:
Combing with regional well-log data,the complicated tectonic movements were explored atcontinental margin of the northeast South China Sea(SCS) such as rifting at Early Cenozoic,phasic extrusion at Late Miocene and stable thermal sedimentation after Pliocene by analy zing high resolution multi-channel seismic profiles acquired in the national "973" project.Therein,the typical extruding inversion structures such as anticlines and reversed faults existing at Mid-Lower Miocene strat a especially in back of to tally rifting evolutionary conditions manifested the phasic extruding tectonic movement occurred at about Late Miocene in the nort heast SCS.Analyzed results show that the inversion structure is the external performance of Dong sha movement.And its dynamic origin is related to the northwest movement of Philippine Sea Plate.
Combing with regional well-log data,the complicated tectonic movements were explored atcontinental margin of the northeast South China Sea(SCS) such as rifting at Early Cenozoic,phasic extrusion at Late Miocene and stable thermal sedimentation after Pliocene by analy zing high resolution multi-channel seismic profiles acquired in the national "973" project.Therein,the typical extruding inversion structures such as anticlines and reversed faults existing at Mid-Lower Miocene strat a especially in back of to tally rifting evolutionary conditions manifested the phasic extruding tectonic movement occurred at about Late Miocene in the nort heast SCS.Analyzed results show that the inversion structure is the external performance of Dong sha movement.And its dynamic origin is related to the northwest movement of Philippine Sea Plate.
2009, 31(3): 84-94.
Abstract:
The chatacteristics of heavy mineral composition and distribution were analyzed in the surface sediment of the Yalu Estuary and its adjacent sea area,and its seabed sediment movement was also discussed.Results indicate that there exist two types of heavy mineral assemblages in the study area,one is biotite-hornllende-epidote,and another can be divided int of our sub-types,is composed of hornllende,epi-dote,and metal minerals(magnetite,ilmenite,hematite and limonite) .Variations of stable heavy mineral and unstable heavy mineral contents,seabed sediment transportrate and direction,and sectional distribution of grain size show that the estuarine seabed sediments in the north of 10 m isobath are transported landwards.This pheno menon is distinct from previous studies,is mainly caused by sel-fadjustment of the Yalu River catchments associating with human activities,especially large hydraulic project construction and sand dredging.Furt hermore,results of heavy mineral analysis also indicates that the estuarine seabed sediments in the south of 10 misobath are mainly directed seaw ards,and the sediments of the adjacent sea area of the Yalu Estuary are transported from the east,as well as the west to the medium.However,these conclusions still need to be furt hertestified using the method of geochemistry and sediment dynamics.Stable heavy mineral contents of garne and tourmalin in the west of the northern Huanghai Sea are larger than those in the east of the northern Huang hai Sea according to the comparison of heavy mineral distributions between these two areas.The mostevident difference among the east of the northern Huanghai Sea from the west of the northern Huanghai Sea,the south and the north of the southern Huanghai Sea,is that autogenetic pyrite does not occur in the sediments of the east of the nor thern Huanghai Sea.
The chatacteristics of heavy mineral composition and distribution were analyzed in the surface sediment of the Yalu Estuary and its adjacent sea area,and its seabed sediment movement was also discussed.Results indicate that there exist two types of heavy mineral assemblages in the study area,one is biotite-hornllende-epidote,and another can be divided int of our sub-types,is composed of hornllende,epi-dote,and metal minerals(magnetite,ilmenite,hematite and limonite) .Variations of stable heavy mineral and unstable heavy mineral contents,seabed sediment transportrate and direction,and sectional distribution of grain size show that the estuarine seabed sediments in the north of 10 m isobath are transported landwards.This pheno menon is distinct from previous studies,is mainly caused by sel-fadjustment of the Yalu River catchments associating with human activities,especially large hydraulic project construction and sand dredging.Furt hermore,results of heavy mineral analysis also indicates that the estuarine seabed sediments in the south of 10 misobath are mainly directed seaw ards,and the sediments of the adjacent sea area of the Yalu Estuary are transported from the east,as well as the west to the medium.However,these conclusions still need to be furt hertestified using the method of geochemistry and sediment dynamics.Stable heavy mineral contents of garne and tourmalin in the west of the northern Huanghai Sea are larger than those in the east of the northern Huang hai Sea according to the comparison of heavy mineral distributions between these two areas.The mostevident difference among the east of the northern Huanghai Sea from the west of the northern Huanghai Sea,the south and the north of the southern Huanghai Sea,is that autogenetic pyrite does not occur in the sediments of the east of the nor thern Huanghai Sea.
2009, 31(3): 95-102.
Abstract:
The correlations between the East Asian winter monsoon(EAWM) changes from solar activity and ENSO periodicities during the mid-Holocene are attempted to rebuild.On the basis of environmental sensitive grain-size population analysis and AMS carbon-14 dating of Core EC2005,located in the mud area in the inner shelf of the East China Sea(ECS) ,a 700 a EAWM evolution between 5.9 and 5.2 ka BP was compared with the GRIP D18O record,the good correlation suggests that inner relationship existsbet ween the EAWM and the climatic changes disclosed by the GRIP icecore.The EAWM strengt hened during the mid-Holocene,which was well in accord with the regional and global climatic changes.The significant periodicities disclosed by power spectral analysis correspond to the solar activity such as the 62 and 11 a periodicities and the modern ENSO 3~8 a periodicity as 6 and 5 a.The ENSO cycles were considered to existduring the mid-Holocene.The periodicities of solar and ENSO activities were revealed by the sedimentary record with high resolution in the mud area of the ECS inner shelf.
The correlations between the East Asian winter monsoon(EAWM) changes from solar activity and ENSO periodicities during the mid-Holocene are attempted to rebuild.On the basis of environmental sensitive grain-size population analysis and AMS carbon-14 dating of Core EC2005,located in the mud area in the inner shelf of the East China Sea(ECS) ,a 700 a EAWM evolution between 5.9 and 5.2 ka BP was compared with the GRIP D18O record,the good correlation suggests that inner relationship existsbet ween the EAWM and the climatic changes disclosed by the GRIP icecore.The EAWM strengt hened during the mid-Holocene,which was well in accord with the regional and global climatic changes.The significant periodicities disclosed by power spectral analysis correspond to the solar activity such as the 62 and 11 a periodicities and the modern ENSO 3~8 a periodicity as 6 and 5 a.The ENSO cycles were considered to existduring the mid-Holocene.The periodicities of solar and ENSO activities were revealed by the sedimentary record with high resolution in the mud area of the ECS inner shelf.
2009, 31(3): 103-112.
Abstract:
Field investigation of intertidal zone macro zoobenthos was carried out in October 2007 in the Jiaojiang Estuary,and fourstations were set up in each of six sampling sections.Analysis of the relation ship between the species number and the station number was conducted,furthermore,beta diversity theory was used to analyze the macrozoo benthos community in the following environmental gradients:(1) the vertical environmental gradient within the intertidal sampling section;(2) the environmental gradient from river to sea;(3) environmental gradient of the distance between two banks of estuary.Main research findings are as follows:(1) With the increase of sampling station number,species number has a uptrend but the variety rate is more and more slow,besides,beta diversity index presents a down trend;(2) beta diversity index has a significant change in different vertical distances within the sampling section;(3) with the raise of spatial scale,beta diversity index presents a upt rend both in north and south banks,and which had a significant correlation with the grain size and oils concentration of sediment;(4) the Jiaojiang Estuary had a trumpet shape,and beta diversity index also presents a growing trend with the increase of the distance between the two banks of the estuary.
Field investigation of intertidal zone macro zoobenthos was carried out in October 2007 in the Jiaojiang Estuary,and fourstations were set up in each of six sampling sections.Analysis of the relation ship between the species number and the station number was conducted,furthermore,beta diversity theory was used to analyze the macrozoo benthos community in the following environmental gradients:(1) the vertical environmental gradient within the intertidal sampling section;(2) the environmental gradient from river to sea;(3) environmental gradient of the distance between two banks of estuary.Main research findings are as follows:(1) With the increase of sampling station number,species number has a uptrend but the variety rate is more and more slow,besides,beta diversity index presents a down trend;(2) beta diversity index has a significant change in different vertical distances within the sampling section;(3) with the raise of spatial scale,beta diversity index presents a upt rend both in north and south banks,and which had a significant correlation with the grain size and oils concentration of sediment;(4) the Jiaojiang Estuary had a trumpet shape,and beta diversity index also presents a growing trend with the increase of the distance between the two banks of the estuary.
2009, 31(3): 113-120.
Abstract:
Seasonal variations of eutrophication in the Zhujiang Estuary were examined based on data from three surveys during the wet,temperate and dry seasons from 2006 to 2007. A modified method of nutrient status index and CN/CP value were used in analysis,and the relation ship bet ween eutrophication index and environmental factors was discussed. It concluded that the eutrophication in the Zhujiang Estuary was high,and this area could be classified as a phosphorus-limited potential eutrophication area. The eutrophication index decreased along the estuary from north to south in spatial distribution,and eutrophication index showed a sequence of dryseasong reater than wet seasong reater than temperate season in the seasonal variation. The temporal and spatial distributions of eutrophication index were mostly regulated by runoff.
Seasonal variations of eutrophication in the Zhujiang Estuary were examined based on data from three surveys during the wet,temperate and dry seasons from 2006 to 2007. A modified method of nutrient status index and CN/CP value were used in analysis,and the relation ship bet ween eutrophication index and environmental factors was discussed. It concluded that the eutrophication in the Zhujiang Estuary was high,and this area could be classified as a phosphorus-limited potential eutrophication area. The eutrophication index decreased along the estuary from north to south in spatial distribution,and eutrophication index showed a sequence of dryseasong reater than wet seasong reater than temperate season in the seasonal variation. The temporal and spatial distributions of eutrophication index were mostly regulated by runoff.
2009, 31(3): 121-126.
Abstract:
Based on the survey data from 1975 to 1998 in the 32°N section,the distributions of temperature,salinity,dissolved oxygen and nutrients as well as their variation trends were analyzed during these 20 a.The climatet rend coefficients and the anomaly pictures of the factors revealed positive trends of nitrate.But dissolved oxygen,phosphate and silicate decreased in spring.The nutrient structure in spring was also discussed.The content of nitrogen was generally low and it was possible to be a limiting-factor for phytoplankton growth in the study area.
Based on the survey data from 1975 to 1998 in the 32°N section,the distributions of temperature,salinity,dissolved oxygen and nutrients as well as their variation trends were analyzed during these 20 a.The climatet rend coefficients and the anomaly pictures of the factors revealed positive trends of nitrate.But dissolved oxygen,phosphate and silicate decreased in spring.The nutrient structure in spring was also discussed.The content of nitrogen was generally low and it was possible to be a limiting-factor for phytoplankton growth in the study area.
2009, 31(3): 127-136.
Abstract:
Eight microsatellite markers were used to estimate the kinship and the genetic diversity of seven turbot(Scophthalmus maximus L.) families. The average polymorphic information content(PIC) and the average heterozy gosity were 0.6721 and 0.7606,respectively. To tally forty alleles were detected at eight microsatellite loci in seven full and hal-fsib families of turbot. The number of the alleles at each locus ranged from three to eight. Based on the genotypes of either known parentor none of them and of fspring, all the absent parental genotypes of the seven families were deduced. According to the uniquealleles among the families,each family could be disting uished from the others. Cervus 3.0 analysis showed that the combined exclusion probability was 97.07% if parents were both unknown and the combined exclusion probability was 99.63% when only one of the parental geno type was known. A dendrogram was constructed using UPGMA based on genetic similarity matrix. The UPGAM dendrogram of the 137 individuals indicated that 90.5% of the individuals from each family could befully clustered and the classification results accorded with the source of genealogy. The results showed that microsatellite marker is useful tool for genealogical identification of turbot.
Eight microsatellite markers were used to estimate the kinship and the genetic diversity of seven turbot(Scophthalmus maximus L.) families. The average polymorphic information content(PIC) and the average heterozy gosity were 0.6721 and 0.7606,respectively. To tally forty alleles were detected at eight microsatellite loci in seven full and hal-fsib families of turbot. The number of the alleles at each locus ranged from three to eight. Based on the genotypes of either known parentor none of them and of fspring, all the absent parental genotypes of the seven families were deduced. According to the uniquealleles among the families,each family could be disting uished from the others. Cervus 3.0 analysis showed that the combined exclusion probability was 97.07% if parents were both unknown and the combined exclusion probability was 99.63% when only one of the parental geno type was known. A dendrogram was constructed using UPGMA based on genetic similarity matrix. The UPGAM dendrogram of the 137 individuals indicated that 90.5% of the individuals from each family could befully clustered and the classification results accorded with the source of genealogy. The results showed that microsatellite marker is useful tool for genealogical identification of turbot.
2009, 31(3): 137-148.
Abstract:
A laboratory experiment of measuring horizontal mixing coefficients was performed in the surfzone on two plane beaches with slopes 1:40 and 1:100 for regular waves.The transport and diffusion of a pointink in longshore currents were recorded by CCD cameras over the beach.Based on anapproximate analytical solution to the depth-averaged two-dimensional convection-diffusion equation,a method of calculating mixing coefficients using experiments data was developed.The result for mixing coefficients show that it only depends on the local water depth and not on the wave parameters such as periods and heights. The dispersion caused by the vertical variation of long shore currents leads to the long shore mixing coefficients much greater than the cross-shore mixing coefficients.The contribution of waves to cross-shore mixing coefficients accounts for 40%,and the rest is due to the turbulence produced by wave breaking.
A laboratory experiment of measuring horizontal mixing coefficients was performed in the surfzone on two plane beaches with slopes 1:40 and 1:100 for regular waves.The transport and diffusion of a pointink in longshore currents were recorded by CCD cameras over the beach.Based on anapproximate analytical solution to the depth-averaged two-dimensional convection-diffusion equation,a method of calculating mixing coefficients using experiments data was developed.The result for mixing coefficients show that it only depends on the local water depth and not on the wave parameters such as periods and heights. The dispersion caused by the vertical variation of long shore currents leads to the long shore mixing coefficients much greater than the cross-shore mixing coefficients.The contribution of waves to cross-shore mixing coefficients accounts for 40%,and the rest is due to the turbulence produced by wave breaking.
2009, 31(3): 149-157.
Abstract:
An analytical method is used to analyze the hydrodynamic characteristics of an array of horizontal pulsating circularcy linders in a two-layers fluid of infinite depth. Under the linear potential theory,analytic expressions for the radiation potential functions are obtained by using the multipole expansion method,and expressions for an added mass and a damping coefficient are defined. After the correct ness of this method was verified by the boundary element method,the hydrodynamic character istics of the array of horizontal circularcy linders are analyzed on two different conditions. It is concluded that the fluid density ratio,the submergence depth,the arrangement and the spacing of cylinders have great impacton the results of the added mass and the damping coefficient.
An analytical method is used to analyze the hydrodynamic characteristics of an array of horizontal pulsating circularcy linders in a two-layers fluid of infinite depth. Under the linear potential theory,analytic expressions for the radiation potential functions are obtained by using the multipole expansion method,and expressions for an added mass and a damping coefficient are defined. After the correct ness of this method was verified by the boundary element method,the hydrodynamic character istics of the array of horizontal circularcy linders are analyzed on two different conditions. It is concluded that the fluid density ratio,the submergence depth,the arrangement and the spacing of cylinders have great impacton the results of the added mass and the damping coefficient.
2009, 31(3): 158-166.
Abstract:
A coupled hydrodynamic-ecological(COH ERENS) model,with anorthogonal horizontal coordinates and a σ-vertical coordinate,was combined with a 3-D Lagrangian drifter tracking module and a water quality module to construct the hydrodynamic part of the modeling system.The COHERENS model was used to study water exchange and pollutant transport in the Changjiang Estuary.The particle tracking method,as applied in the sing lerelease experiments,provides a picture of the residual flow in the certain parts of the Changjiang Estuary.The COHERENS model had been modified by means of the changing grid technology and the dry-wet method to deal with the moving boundary.The model was calibrated and validated using tidal data available for represent ativestations.Both the magnitude and phase of the water elevation and velocity were reasonably reproduced.The numerical simulation was performed of the tidal current and pollutant diffusion from the Xuliu River node transect in the Changjiang Estuary to reveal suspended particle matter and dissolved pollutant transport in this area.By calculation of the track of Lagrange particle(or particles mass centre) and Eulerian dissolved contaminant mass centre realsed from the Xuliu River node transect,the effects of current fields on the pollutant transport and diffusion were analyzed. The current field characteristics and the pollutant transport rule were discovered.
A coupled hydrodynamic-ecological(COH ERENS) model,with anorthogonal horizontal coordinates and a σ-vertical coordinate,was combined with a 3-D Lagrangian drifter tracking module and a water quality module to construct the hydrodynamic part of the modeling system.The COHERENS model was used to study water exchange and pollutant transport in the Changjiang Estuary.The particle tracking method,as applied in the sing lerelease experiments,provides a picture of the residual flow in the certain parts of the Changjiang Estuary.The COHERENS model had been modified by means of the changing grid technology and the dry-wet method to deal with the moving boundary.The model was calibrated and validated using tidal data available for represent ativestations.Both the magnitude and phase of the water elevation and velocity were reasonably reproduced.The numerical simulation was performed of the tidal current and pollutant diffusion from the Xuliu River node transect in the Changjiang Estuary to reveal suspended particle matter and dissolved pollutant transport in this area.By calculation of the track of Lagrange particle(or particles mass centre) and Eulerian dissolved contaminant mass centre realsed from the Xuliu River node transect,the effects of current fields on the pollutant transport and diffusion were analyzed. The current field characteristics and the pollutant transport rule were discovered.
2009, 31(3): 167-174.
Abstract:
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