2012 Vol. 34, No. 5
Display Method:
2012, 34(5): 1-10.
Abstract:
Bering Strait is the only channel connecting the Pacific Ocean and the Arctic Ocean.The Pacific water through the strait is mainly driven by the meridional sea level slop and its inter-annual variation has great influence on the Arctic Ocean. In this study SODA data is applied to the calculation of the monthly mean volume transport through Bering Strait. The factors related to the inter-annual variability of summer volume transport are discussed.The results show that the SSH in the Laptev Sea, the East Siberian Sea, the Chukchi Sea, south of the Beaufort Sea is negatively correlated to the volume transport of Bering Strait in inter-annual scale while the situation is opposite in the eastern shelf of Bering Sea.After analyzing the correlation of the volume flux with the Ekman transport, pumping rate, upper layer salinity, temperature and density, the paper find that the Ekman transport anomaly should be responsible for the relationship between the sea surface height and the volume flux of Bering Strait. When the SLP is positive anomaly over central part of the Arctic Ocean and negative anomaly over Bering Sea basin, the volume transport through Bering Strait will be enlarged. Such SLP anomaly would explain the relationship between the Bering Strait volume transport and the Ekman transport, pumping rate and upper layer water properties to some extend. The paper reveals that the summer SLP’s inter-annual variation can change SSH via Ekman transport and finally dominant the volume transport through Bering Strait.
Bering Strait is the only channel connecting the Pacific Ocean and the Arctic Ocean.The Pacific water through the strait is mainly driven by the meridional sea level slop and its inter-annual variation has great influence on the Arctic Ocean. In this study SODA data is applied to the calculation of the monthly mean volume transport through Bering Strait. The factors related to the inter-annual variability of summer volume transport are discussed.The results show that the SSH in the Laptev Sea, the East Siberian Sea, the Chukchi Sea, south of the Beaufort Sea is negatively correlated to the volume transport of Bering Strait in inter-annual scale while the situation is opposite in the eastern shelf of Bering Sea.After analyzing the correlation of the volume flux with the Ekman transport, pumping rate, upper layer salinity, temperature and density, the paper find that the Ekman transport anomaly should be responsible for the relationship between the sea surface height and the volume flux of Bering Strait. When the SLP is positive anomaly over central part of the Arctic Ocean and negative anomaly over Bering Sea basin, the volume transport through Bering Strait will be enlarged. Such SLP anomaly would explain the relationship between the Bering Strait volume transport and the Ekman transport, pumping rate and upper layer water properties to some extend. The paper reveals that the summer SLP’s inter-annual variation can change SSH via Ekman transport and finally dominant the volume transport through Bering Strait.
2012, 34(5): 11-19.
Abstract:
In order to improve the sub-grid effect,a method for automatically computing the energy flux transparency in WAVEWATCH-Ⅲ model has been established basing on the optimization of computing grid by using depth and high resolution coastlines.The results with the improving sub-grid effect are compared with that directly increasing grid resolution to identify out islands.It shows that the improving sub-grid effect could adequately describe the effect of multi-islands and complex terrain on wave spreading by restraining low-frequency wave energy and the simulation results are well improved.By improving sub-grid effect in low resolution grid,the calculation efficiency is highly increased and the accuracy of significant wave height is equivalent with the results using high resolution grid.
In order to improve the sub-grid effect,a method for automatically computing the energy flux transparency in WAVEWATCH-Ⅲ model has been established basing on the optimization of computing grid by using depth and high resolution coastlines.The results with the improving sub-grid effect are compared with that directly increasing grid resolution to identify out islands.It shows that the improving sub-grid effect could adequately describe the effect of multi-islands and complex terrain on wave spreading by restraining low-frequency wave energy and the simulation results are well improved.By improving sub-grid effect in low resolution grid,the calculation efficiency is highly increased and the accuracy of significant wave height is equivalent with the results using high resolution grid.
2012, 34(5): 20-30.
Abstract:
To analyze the cause of irregular period tidal currents called "four floods and four ebbs" at the mouth of the upper North Branch in Changjiang River estuary during spring tides in dry season, the paper simulated the dynamic mechanism by means of numerical simulation and momentum analysis. The results showed that two flood currents and two ebb currents controlled by semidiurnal tide were regular period tidal currents, while the other two flood currents and two ebb currents were irregular in one day. The irregular flood currents happened with little velocity and short duration of about 2 h in a small range, meanwhile, the ebb currents in the South Branch were in the late stage. At the surface layer, the southward vertical diffusion played a decisive role, as well as the advection and the surface elevation gradient. While the baroclinic pressure gradient, which generated by the salinity front, reacted with the surface elevation gradient at the bottom layer. It indicated that the irregular flood currents at the mouth of the upper North Branch were mainly caused by the north wind stress, southward baroclinic pressure gradient forcing and the tractive action of the late ebb currents in the South Branch. The duration decreased exponentially with river discharge and disappeared when the value was greater than 22 300 m3/s. The irregular ebb currents occurred with large velocity and duration of 2.5 h in a larger area. The water mass in the South Branch spilled over into the North Branch for the earlier flood currents and formed the irregular ebb currents at the upper North Branch. The vertical diffusion, as well as the advection, did the work with the surface elevation gradient forcing from surface to bottom layers. It showed the dynamic mechanism and process of the irregular flood and ebb currents as stated above.
To analyze the cause of irregular period tidal currents called "four floods and four ebbs" at the mouth of the upper North Branch in Changjiang River estuary during spring tides in dry season, the paper simulated the dynamic mechanism by means of numerical simulation and momentum analysis. The results showed that two flood currents and two ebb currents controlled by semidiurnal tide were regular period tidal currents, while the other two flood currents and two ebb currents were irregular in one day. The irregular flood currents happened with little velocity and short duration of about 2 h in a small range, meanwhile, the ebb currents in the South Branch were in the late stage. At the surface layer, the southward vertical diffusion played a decisive role, as well as the advection and the surface elevation gradient. While the baroclinic pressure gradient, which generated by the salinity front, reacted with the surface elevation gradient at the bottom layer. It indicated that the irregular flood currents at the mouth of the upper North Branch were mainly caused by the north wind stress, southward baroclinic pressure gradient forcing and the tractive action of the late ebb currents in the South Branch. The duration decreased exponentially with river discharge and disappeared when the value was greater than 22 300 m3/s. The irregular ebb currents occurred with large velocity and duration of 2.5 h in a larger area. The water mass in the South Branch spilled over into the North Branch for the earlier flood currents and formed the irregular ebb currents at the upper North Branch. The vertical diffusion, as well as the advection, did the work with the surface elevation gradient forcing from surface to bottom layers. It showed the dynamic mechanism and process of the irregular flood and ebb currents as stated above.
2012, 34(5): 31-38.
Abstract:
Based on long time hydrological reanalysis data from Japan Meteorological Agency, the heat transportof Kuroshio (KHT) east of Taiwan on the characteristic section (24°N Section) was estimated by using the dynamical method, and its lower frequency variability was analyzed with wavelet transform technique.Then, the relation between the KHT anomaly and the SSTA in China adjacent seas, as well as the implications of the pre-seasons(autumn, winter and spring) and homachronous(summer) KHT anomaly for summer rainfall anomaly over the Chinese mainland were discussed.The results show that, the KHT east of Taiwan presents notably quasi-2 a and around 16 a variations which were subject to temporal variety and seasonal discrepancy.There is a linear increasing trend in the heat transport for more than 50 years, while its magnitude is small and the long-term trends in four seasons are dissimilar.The correlation analysis suggests that, the KHT east of Taiwan is likely to be an important factor to impact the SST anomalous variation in east China seas on long time scale.And the regression analysis indicates that, the preceding and contemporaneous KHT anomalies east of Taiwan have strong implications for the summer rainfall variations over the east of the mainland with seasonal discrepancy.
Based on long time hydrological reanalysis data from Japan Meteorological Agency, the heat transportof Kuroshio (KHT) east of Taiwan on the characteristic section (24°N Section) was estimated by using the dynamical method, and its lower frequency variability was analyzed with wavelet transform technique.Then, the relation between the KHT anomaly and the SSTA in China adjacent seas, as well as the implications of the pre-seasons(autumn, winter and spring) and homachronous(summer) KHT anomaly for summer rainfall anomaly over the Chinese mainland were discussed.The results show that, the KHT east of Taiwan presents notably quasi-2 a and around 16 a variations which were subject to temporal variety and seasonal discrepancy.There is a linear increasing trend in the heat transport for more than 50 years, while its magnitude is small and the long-term trends in four seasons are dissimilar.The correlation analysis suggests that, the KHT east of Taiwan is likely to be an important factor to impact the SST anomalous variation in east China seas on long time scale.And the regression analysis indicates that, the preceding and contemporaneous KHT anomalies east of Taiwan have strong implications for the summer rainfall variations over the east of the mainland with seasonal discrepancy.
2012, 34(5): 39-49.
Abstract:
The bottom boundary layer (BBL) flows are the important processes in estuarine and coastal dynamics and sediment transport.A high-frequency acoustic doppler velocimeter (ADV) has become the most effective tool in the BBL turbulence observations.Unfortunately, the filed observations are frequently interfered by the status of ADV-attached frame stability, and raw data is significantly contaminated by ambient waves and currents, bedforms and so on.To date, the post-processing procedure for turbulence parameters is far from being a standard method.On the basis of previous works, the paper proposed a comprehensive technical method for the post-processing, including status check, data quality control, coordinate rotation, despiking and filtering.Some potential errors arisen from these processing processes were analyzed in a greater detail,and the evaluation in accuracy of post-processing was discussed.The present contribution may provide a technical support for the ground-truth investigation of turbulent mixing and sediment transport in the coastal ocean.
The bottom boundary layer (BBL) flows are the important processes in estuarine and coastal dynamics and sediment transport.A high-frequency acoustic doppler velocimeter (ADV) has become the most effective tool in the BBL turbulence observations.Unfortunately, the filed observations are frequently interfered by the status of ADV-attached frame stability, and raw data is significantly contaminated by ambient waves and currents, bedforms and so on.To date, the post-processing procedure for turbulence parameters is far from being a standard method.On the basis of previous works, the paper proposed a comprehensive technical method for the post-processing, including status check, data quality control, coordinate rotation, despiking and filtering.Some potential errors arisen from these processing processes were analyzed in a greater detail,and the evaluation in accuracy of post-processing was discussed.The present contribution may provide a technical support for the ground-truth investigation of turbulent mixing and sediment transport in the coastal ocean.
2012, 34(5): 50-58.
Abstract:
With the deepening of the ocean research, more and more demands on the quality of observational data are proposed. In order to effectively reduce the uncertainty of the measured data, the measured temperature and salinity data related to the seawater CO2 partial pressure was taken as an example. As the instrument platform can measure multi-parameter simultaneously, and the measurement indicators can be assumed to change stably in small time and space range. On this basis, most of the original observation sequences were confirmed to meet the hypothesis of second-order differential smoothness by ADF stationary test theory. Then, an expression for observation data uncertainty based on the differential statistical characteristic of observation sequence, and an algorithm of multi-parameter difference correlation Federated Filter based on the outliers recognition, are proposed in this paper. Comparing with the common filtering algorithm, it was found that the new algorithm can effectively integrate the relevant information of parameters, reduce the uncertainty of the sequence, and maximize the protection of the original measurement data.
With the deepening of the ocean research, more and more demands on the quality of observational data are proposed. In order to effectively reduce the uncertainty of the measured data, the measured temperature and salinity data related to the seawater CO2 partial pressure was taken as an example. As the instrument platform can measure multi-parameter simultaneously, and the measurement indicators can be assumed to change stably in small time and space range. On this basis, most of the original observation sequences were confirmed to meet the hypothesis of second-order differential smoothness by ADF stationary test theory. Then, an expression for observation data uncertainty based on the differential statistical characteristic of observation sequence, and an algorithm of multi-parameter difference correlation Federated Filter based on the outliers recognition, are proposed in this paper. Comparing with the common filtering algorithm, it was found that the new algorithm can effectively integrate the relevant information of parameters, reduce the uncertainty of the sequence, and maximize the protection of the original measurement data.
2012, 34(5): 59-64.
Abstract:
The North-west Pacific (NWP) Ocean is one of the places that have the maximal frequency of tropical cyclones (TC) and the highest intensity of TCs in the world.It is significant to investigate the characteristics of TCs in the NWP.Nephogram is an important tool for monitoring tropical cyclone and typhoon in the tropical ocean,effective classification of image data and the segmentation of typhoon cloud are key steps for subsequent image feature extraction.Matching pursuit is one of the most important algorithm in signal processing and of vast application remote sensing image pattern recognition.In the paper,Matching pursuit algorithm is proposed to realize typhoon feature extraction in the NWP.Although the veracity is needed to be improved,the algorithm could efficiency segment the main typhoon cloud systems,and can satisfy typhoon forecast and monitoring well in the meteorological applications.
The North-west Pacific (NWP) Ocean is one of the places that have the maximal frequency of tropical cyclones (TC) and the highest intensity of TCs in the world.It is significant to investigate the characteristics of TCs in the NWP.Nephogram is an important tool for monitoring tropical cyclone and typhoon in the tropical ocean,effective classification of image data and the segmentation of typhoon cloud are key steps for subsequent image feature extraction.Matching pursuit is one of the most important algorithm in signal processing and of vast application remote sensing image pattern recognition.In the paper,Matching pursuit algorithm is proposed to realize typhoon feature extraction in the NWP.Although the veracity is needed to be improved,the algorithm could efficiency segment the main typhoon cloud systems,and can satisfy typhoon forecast and monitoring well in the meteorological applications.
2012, 34(5): 65-73.
Abstract:
For the assimilation of altimeter data,the influence of different analysis schemes on the assimilation effects is analyzed.Differing in the inversion methods of a background error covariance matrix,these schemes include a empirical orthogonal function scheme and its variant variance form(abbreviated as EOF and EOF_var),a recursive filter scheme and its variant variance form(abbreviated as RF and RF_var),and a matrix inversion using a elementary transformation method(abbreviated as Inv).Using the above schemes,some assimilation experiments,based on TOPEX/Poseidon satellite altimeter data from January to July 2002,were carried out in tropical Pacific Ocean,and then the assimilation effects were assessed using SODA reanalysis data and TAO observations.On the one hand,the comparison with the SODA data shows that the Inv scheme has less improvement on the modeling temperature field,and the other four schemes improve the model fields more clearly in depth from 100 to 300 m and less in other range.On the other hand,the comparison with the TAO observations indicates that the EOF_var and RF_var are the most effective scheme to improve temperature field,next are the EOF and RF schemes,least is Inv scheme.
For the assimilation of altimeter data,the influence of different analysis schemes on the assimilation effects is analyzed.Differing in the inversion methods of a background error covariance matrix,these schemes include a empirical orthogonal function scheme and its variant variance form(abbreviated as EOF and EOF_var),a recursive filter scheme and its variant variance form(abbreviated as RF and RF_var),and a matrix inversion using a elementary transformation method(abbreviated as Inv).Using the above schemes,some assimilation experiments,based on TOPEX/Poseidon satellite altimeter data from January to July 2002,were carried out in tropical Pacific Ocean,and then the assimilation effects were assessed using SODA reanalysis data and TAO observations.On the one hand,the comparison with the SODA data shows that the Inv scheme has less improvement on the modeling temperature field,and the other four schemes improve the model fields more clearly in depth from 100 to 300 m and less in other range.On the other hand,the comparison with the TAO observations indicates that the EOF_var and RF_var are the most effective scheme to improve temperature field,next are the EOF and RF schemes,least is Inv scheme.
2012, 34(5): 74-80.
Abstract:
Petroleum substance for water body pollution has been the focus of attention of the world.an oil fire and explosion of Dalian Bay oil pipeline cause oil spill into the event,the water as well as the ocean to the ecological environment has caused enormous disaster,this makes from remote sensing technology perspective how effectively and accurately monitoring water petroleum substance change process,mobile path,the spatial distribution mentioned as schedule.The petroleum pollutant is one of organic contamination in water and it has showed by the present research that the influence of petroleum concentration in water on spectral absorption coefficient is mainly represented on absorption spectral features of yellow substance.In the fields of water colour remote sensing,optical absorption properties are mainly described with the absorption coefficient and the spectral slope.The experimental data including the absorption coefficient of CDOM,apparent optical properties and petroleum pollutant concentration are obtained in the regions of Panjin,Liaoning Province,China in May 2008, August 2009 and June 2010.With the measurement data,the exponential spectral slope was determined;the remote sensing model was establish based on the exponential spectral slope and the absorption coefficient at 440nm,then the validation was done with thirty-one samples.The result shows that the relative error is 6.884 7%.The model for water petroleum concentration retrieved from HJ-1 satellite is applied in the region of Liaodong Gulf.
Petroleum substance for water body pollution has been the focus of attention of the world.an oil fire and explosion of Dalian Bay oil pipeline cause oil spill into the event,the water as well as the ocean to the ecological environment has caused enormous disaster,this makes from remote sensing technology perspective how effectively and accurately monitoring water petroleum substance change process,mobile path,the spatial distribution mentioned as schedule.The petroleum pollutant is one of organic contamination in water and it has showed by the present research that the influence of petroleum concentration in water on spectral absorption coefficient is mainly represented on absorption spectral features of yellow substance.In the fields of water colour remote sensing,optical absorption properties are mainly described with the absorption coefficient and the spectral slope.The experimental data including the absorption coefficient of CDOM,apparent optical properties and petroleum pollutant concentration are obtained in the regions of Panjin,Liaoning Province,China in May 2008, August 2009 and June 2010.With the measurement data,the exponential spectral slope was determined;the remote sensing model was establish based on the exponential spectral slope and the absorption coefficient at 440nm,then the validation was done with thirty-one samples.The result shows that the relative error is 6.884 7%.The model for water petroleum concentration retrieved from HJ-1 satellite is applied in the region of Liaodong Gulf.
2012, 34(5): 81-90.
Abstract:
Transparent exopolymer particles (TEP) are large, sticky particles in marine environments, and play a significant role in particle dynamics, carbon export, food web energy transfer and scavenging of trace metals. Samples were collected from the northern Bering Sea during summer 2010 for measurements of TEP and other hydrographic parameters to examine the abundance, distributions and sources of TEP. Our results showed that TEP concentrations ranged from 34 to 628 mg/m3(Xeq). The averaged TEP concentrations in the shelf, slope and basin were 240, 145 and 83 mg/m3(Xeq), respectively, showing a general decrease from the shelf to the basin. In the slope and basin areas, TEP concentrations decreased with the increasing depth. However, high concentrations of TEP were observed in the shelf bottom waters, coincided with the high values of TSM and POC. The correlations between TEP and fluorescence, TSM and POC suggested two sources of TEP in the northern Bering Sea: (1) in situ production from planktons in the upper water column, and (2) benthic biological processes in the sediments. High TEP concentrations in the shelf bottom waters was predominantly derived from sediment resuspension, which may have a potential effect on carbon biogeochemical cycle and scavenging of trace elements in shelf regions.
Transparent exopolymer particles (TEP) are large, sticky particles in marine environments, and play a significant role in particle dynamics, carbon export, food web energy transfer and scavenging of trace metals. Samples were collected from the northern Bering Sea during summer 2010 for measurements of TEP and other hydrographic parameters to examine the abundance, distributions and sources of TEP. Our results showed that TEP concentrations ranged from 34 to 628 mg/m3(Xeq). The averaged TEP concentrations in the shelf, slope and basin were 240, 145 and 83 mg/m3(Xeq), respectively, showing a general decrease from the shelf to the basin. In the slope and basin areas, TEP concentrations decreased with the increasing depth. However, high concentrations of TEP were observed in the shelf bottom waters, coincided with the high values of TSM and POC. The correlations between TEP and fluorescence, TSM and POC suggested two sources of TEP in the northern Bering Sea: (1) in situ production from planktons in the upper water column, and (2) benthic biological processes in the sediments. High TEP concentrations in the shelf bottom waters was predominantly derived from sediment resuspension, which may have a potential effect on carbon biogeochemical cycle and scavenging of trace elements in shelf regions.
2012, 34(5): 91-99.
Abstract:
Hierarchical clustering and factor analysis are respectively applied to the grain size composition of 283 surface sediment samples and the mineral analysis of 85 sediment samples collected in the Taiwan Strait. The results show that the surface sediments contain six kinds of sediment types in the Taiwan Strait, they can be divided into three types of depositional environment areas corresponding to sedimentary dynamics properties. Sixty-one kinds of minerals were found in the surface sediment samples, light minerals are main, with average content up to 97.73%,14 kinds of light minerals were found. The content of heavy minerals is low, with an average of 2.27%,47 kinds of heavy minerals were found. The most important factor that influences the mineral distribution and content variation of the surface sediment in the Taiwan Strait is matter source, followed by hydrodynamic conditions and mineral own metamorphic degree, etc. The main matter source of the sediment in the Taiwan Strait includes the detrital matter from the rivers in Fujian Province and Taiwan Province, the erosion and denuded substances from both sides of the Taiwan Stait, Hanjiang River and parts from the Changjiang River and the Qiantang River substances carried by the Zhejiang and Fujian coastal current, the residue in the Taiwan Strait of late Pleistocene and some authigenic minerals,etc.
Hierarchical clustering and factor analysis are respectively applied to the grain size composition of 283 surface sediment samples and the mineral analysis of 85 sediment samples collected in the Taiwan Strait. The results show that the surface sediments contain six kinds of sediment types in the Taiwan Strait, they can be divided into three types of depositional environment areas corresponding to sedimentary dynamics properties. Sixty-one kinds of minerals were found in the surface sediment samples, light minerals are main, with average content up to 97.73%,14 kinds of light minerals were found. The content of heavy minerals is low, with an average of 2.27%,47 kinds of heavy minerals were found. The most important factor that influences the mineral distribution and content variation of the surface sediment in the Taiwan Strait is matter source, followed by hydrodynamic conditions and mineral own metamorphic degree, etc. The main matter source of the sediment in the Taiwan Strait includes the detrital matter from the rivers in Fujian Province and Taiwan Province, the erosion and denuded substances from both sides of the Taiwan Stait, Hanjiang River and parts from the Changjiang River and the Qiantang River substances carried by the Zhejiang and Fujian coastal current, the residue in the Taiwan Strait of late Pleistocene and some authigenic minerals,etc.
2012, 34(5): 100-110.
Abstract:
The variation of suspended sediment concentration (SSC) under different waves imposed on sea-bed soils, collected from the modern Huanghe River Delta,is observed in a laboratory flume experiment. Resuspension flux per unit area of sea-bed in different wave heights and action time has been analyzed, together with the settling pattern of sediment in static water since wave stopped.It is shown that the resuspension flux of sea-bed sediments increases with the wave height under a certain water depth with a good linear fitting relationship;the resuspension of sea-bed sediments experiences about 5 000~6 000 wave cycles under the continuous action of certain height waves. At the primary stage of wave action, the difference between the low layer concentration and the middle-upper layer concentration is significant, the vertical concentration structure presents a slanted type. After the distribution of SSC in each water layer is stable,the ratio of SSC on the bottom to that on the surface is about 0.96-1.98 and the SSC uniformly distributes in the whole water.During the hydrostatic sedimentation process,the SSC presents a law of exponential attenuation over time and there is a good negative linear correlation between the SSC and the settlement flux when the SSC is high (greater than 1 g/dm3). The findings can be used for reference in the understanding of wave-induced resuspension process of silty sea-bed sediments in the subaqueous Huanghe River Delta.
The variation of suspended sediment concentration (SSC) under different waves imposed on sea-bed soils, collected from the modern Huanghe River Delta,is observed in a laboratory flume experiment. Resuspension flux per unit area of sea-bed in different wave heights and action time has been analyzed, together with the settling pattern of sediment in static water since wave stopped.It is shown that the resuspension flux of sea-bed sediments increases with the wave height under a certain water depth with a good linear fitting relationship;the resuspension of sea-bed sediments experiences about 5 000~6 000 wave cycles under the continuous action of certain height waves. At the primary stage of wave action, the difference between the low layer concentration and the middle-upper layer concentration is significant, the vertical concentration structure presents a slanted type. After the distribution of SSC in each water layer is stable,the ratio of SSC on the bottom to that on the surface is about 0.96-1.98 and the SSC uniformly distributes in the whole water.During the hydrostatic sedimentation process,the SSC presents a law of exponential attenuation over time and there is a good negative linear correlation between the SSC and the settlement flux when the SSC is high (greater than 1 g/dm3). The findings can be used for reference in the understanding of wave-induced resuspension process of silty sea-bed sediments in the subaqueous Huanghe River Delta.
2012, 34(5): 111-115.
Abstract:
In order to analyze the evolvement and characteristics of muddy tidal flat, a modified formula, verified to be correct by the field survey data in 2000 and 2007,is used to simulate the evolvement condition of muddy tidal flat. The results show that from 1987 to 2010, the slope of muddy tidal flat increases slowly with the speed of 0.022×10-3 in Cangzhou City of Hebei Province; the slope above 0 m bathymetric line decreases gradually with the speed of 0.021×10-3, while it increases with the speed of 0.022×10-3 below the 0 m bathymetric line; and the muddy tidal flat was in the equilibrium state, and the slope would increase in study area. The formulation and conclusions are very important for the protection of muddy tidal flat, and can provide the practical reference on the development and management of muddy tidal flat scientifically.
In order to analyze the evolvement and characteristics of muddy tidal flat, a modified formula, verified to be correct by the field survey data in 2000 and 2007,is used to simulate the evolvement condition of muddy tidal flat. The results show that from 1987 to 2010, the slope of muddy tidal flat increases slowly with the speed of 0.022×10-3 in Cangzhou City of Hebei Province; the slope above 0 m bathymetric line decreases gradually with the speed of 0.021×10-3, while it increases with the speed of 0.022×10-3 below the 0 m bathymetric line; and the muddy tidal flat was in the equilibrium state, and the slope would increase in study area. The formulation and conclusions are very important for the protection of muddy tidal flat, and can provide the practical reference on the development and management of muddy tidal flat scientifically.
2012, 34(5): 116-119.
Abstract:
In order to study the gas hydrate thermal affection on hot water flooding dissociation frontal brim, the mathematical models of dissociation frontal brim counting hydrates saturation in the porous medium have been established and solved with an interactive method. The frontal brims of temperature probe and resistance from experiments fit well to the mathematical model matching and the errors are controlled less than 8%.The thermal factor infections of the hot water flooding temperatures and flooding rates on the dissociation frontal brim are analyzed.The errors of the temperature influence on the dissociation frontal brim are lesser than 8.71% and the influence errors of flooding rates on the dissociation frontal brim are 4.53%.The thermal infections on the hydrate dissociation frontal brim of hydrates can be lessened by rising injected hydrothermal temperatures with massive flowing rates.
In order to study the gas hydrate thermal affection on hot water flooding dissociation frontal brim, the mathematical models of dissociation frontal brim counting hydrates saturation in the porous medium have been established and solved with an interactive method. The frontal brims of temperature probe and resistance from experiments fit well to the mathematical model matching and the errors are controlled less than 8%.The thermal factor infections of the hot water flooding temperatures and flooding rates on the dissociation frontal brim are analyzed.The errors of the temperature influence on the dissociation frontal brim are lesser than 8.71% and the influence errors of flooding rates on the dissociation frontal brim are 4.53%.The thermal infections on the hydrate dissociation frontal brim of hydrates can be lessened by rising injected hydrothermal temperatures with massive flowing rates.
2012, 34(5): 120-127.
Abstract:
The DEM model is established using the bathymetric maps of years of 1977,1994,2003 and 2010,and combined with the 2D model,the evolution of a sand bar in the Huangmao Bay and its formation are studiod in recent 30 a.show that the sandtbar moves to the sea and becemes smaller,its inner slope and top are scoured and outer slope is silted.The formation of the sand bar is mainly located in the weak dynamic zone of the transitional zone between flood flow dominant and ebb flow dominant zones.The decrease of the tidal volume,the weakening of the tidal dynamics and the relative strengthening of the runoff caused by large reclamation,which result in that the ebb flow controlled zone is enlarged,the flood flow controlled zone reduces and the transitional zone moves down,are the main reasons of the sand bar evolution.The reduction of sediment transported by the runoff also contributes to the sand bar evolution.
The DEM model is established using the bathymetric maps of years of 1977,1994,2003 and 2010,and combined with the 2D model,the evolution of a sand bar in the Huangmao Bay and its formation are studiod in recent 30 a.show that the sandtbar moves to the sea and becemes smaller,its inner slope and top are scoured and outer slope is silted.The formation of the sand bar is mainly located in the weak dynamic zone of the transitional zone between flood flow dominant and ebb flow dominant zones.The decrease of the tidal volume,the weakening of the tidal dynamics and the relative strengthening of the runoff caused by large reclamation,which result in that the ebb flow controlled zone is enlarged,the flood flow controlled zone reduces and the transitional zone moves down,are the main reasons of the sand bar evolution.The reduction of sediment transported by the runoff also contributes to the sand bar evolution.
2012, 34(5): 128-138.
Abstract:
In order to better understand the effects of different nitrogen-phosphorus (N/P) ratios (1:1,4:1,8:1,16:1,32:1,64:1,128:1 and 256:1) on phytoplankton community structure,a microcosm experiment was conducted for 30 days during the autumn near Dongtou Island in the East China Sea.The results indicated that the diversity indices,species composition and community succession of the phytoplankton community varied significantly with the N/P ratios.The values of H',Ma,J and Dr were lower in the low N/P ratio treatment (1:1) during the early phase of culture (day 6 to 12),while the values of H',J and Dr were lower in the 8:1 and 16:1 treatments at the end of culture.On the other hand,a higher cell abundance of diatom was observed in the high N/P ratio treatments (128:1 and 256:1) on day 6 and in the 8:1 and 16:1 treatments on day 30.Moreover,a definite community succession order from diatoms to dinoflagellates was observed in all treatments which was in accordance with the result reported in other studies conducted in the East China Sea,therefore,we speculate that the order of phytoplankton succession cultured (enclosure or in-laboratory) was related to the changed environment factors rather than its initial composition.
In order to better understand the effects of different nitrogen-phosphorus (N/P) ratios (1:1,4:1,8:1,16:1,32:1,64:1,128:1 and 256:1) on phytoplankton community structure,a microcosm experiment was conducted for 30 days during the autumn near Dongtou Island in the East China Sea.The results indicated that the diversity indices,species composition and community succession of the phytoplankton community varied significantly with the N/P ratios.The values of H',Ma,J and Dr were lower in the low N/P ratio treatment (1:1) during the early phase of culture (day 6 to 12),while the values of H',J and Dr were lower in the 8:1 and 16:1 treatments at the end of culture.On the other hand,a higher cell abundance of diatom was observed in the high N/P ratio treatments (128:1 and 256:1) on day 6 and in the 8:1 and 16:1 treatments on day 30.Moreover,a definite community succession order from diatoms to dinoflagellates was observed in all treatments which was in accordance with the result reported in other studies conducted in the East China Sea,therefore,we speculate that the order of phytoplankton succession cultured (enclosure or in-laboratory) was related to the changed environment factors rather than its initial composition.
2012, 34(5): 139-146.
Abstract:
Insulin-like growth factor-binding proteins (IGFBPs) play a vital role in regulating the biological activities of IGFs. The full-length cDNA sequences of Scophthalmus maximus IGFBP-1,-2 were cloned and determined by degenerate primer PCR amplification and RACE cDNA amplification for the first time. Both amino acid sequences of IGFBPs can be divided into three domains,the conserved N-terminal domain,the C-terminal domain,and the variable central L-domain. The N-domain and C-domain contain 18 cysteine residues. A local motif (GCGCCXXC) is well conserved within the N-terminal domain and the conserved CWCV motif in C-domain. These motifs have an important role in the binding of IGFBPs to IGFs. Tissue expression analysis showed that igfbp-1 mRNA is highly expressed in liver and spleen, and lower in other tissues. igbfp-2 mRNA is widely expressed in all tissues except muscle. Strong amplification signals were detected in liver, brain, heart, kidney and intestine. This widely expressed pattern suggests that IGFBP has autocrine/paracrine actions on regulating IGFs. The expression analysis during embryonic and larval developmental stages showed that igfbp-1 mRNA could be detected during the whole developmental stages and igfbp-2 mRNA was first detected in the egg of embryoid stage. The mRNA expression suggests that igfbp-1,-2 may play important physiological roles in cell growth as well as in organ differentiation during the embryonic developmental stages.
Insulin-like growth factor-binding proteins (IGFBPs) play a vital role in regulating the biological activities of IGFs. The full-length cDNA sequences of Scophthalmus maximus IGFBP-1,-2 were cloned and determined by degenerate primer PCR amplification and RACE cDNA amplification for the first time. Both amino acid sequences of IGFBPs can be divided into three domains,the conserved N-terminal domain,the C-terminal domain,and the variable central L-domain. The N-domain and C-domain contain 18 cysteine residues. A local motif (GCGCCXXC) is well conserved within the N-terminal domain and the conserved CWCV motif in C-domain. These motifs have an important role in the binding of IGFBPs to IGFs. Tissue expression analysis showed that igfbp-1 mRNA is highly expressed in liver and spleen, and lower in other tissues. igbfp-2 mRNA is widely expressed in all tissues except muscle. Strong amplification signals were detected in liver, brain, heart, kidney and intestine. This widely expressed pattern suggests that IGFBP has autocrine/paracrine actions on regulating IGFs. The expression analysis during embryonic and larval developmental stages showed that igfbp-1 mRNA could be detected during the whole developmental stages and igfbp-2 mRNA was first detected in the egg of embryoid stage. The mRNA expression suggests that igfbp-1,-2 may play important physiological roles in cell growth as well as in organ differentiation during the embryonic developmental stages.
2012, 34(5): 147-153.
Abstract:
The mitochondrial genomic DNA of Alpheus japonicus was obtained by genomic DNA extraction combined with universal primers PCR and long PCR amplification. The complete mitochondrial genome sequence was sequenced using shotgun and primer-walking strategies. Comparative analyses were done combined with A. distinguendus mitochondrial genome, including the basic characteristics, gene order, protein-coding genes, selection pressure, and different sites and so on. The results show that overlapping is found in nine pairs genes of A. japonicus mitochondrial genome. The A. japonicus mitochondrial genome is 16 487 bp in length and is longer than A. distinguendus mitochondrial genome (15 700 bp), mainly due to the length difference of the largest non-coding region. The mitochondrial genomes of A. japonicus and A. distinguendus both contain 37 genes. Gene order of the A. japonicus and A. distinguendus mitochondrial genomes is identical. The translocation of one transfer RNA gene (trnE) involving inversion is found in 2 Alpheus mitochondrial genomes when compared with the pancrustacean ground pattern. There are differences in the usage of start codon and stop codon in protein-coding genes of 2 Alpheus mitochondrial genomes. Except for the cob gene, the numbers of amino acids encoded by the remaining 12 protein-coding genes are identical. The Ka/Ks ratio of all 13 mitochondrial protein coding genes is much lower than 1, indicating a strong negative selection. In 15 major coding genes, nad5 has the largest number of different loci, followed by nad4 and lrRNA genes, can be used as alternative molecular markers to analyze biodiversity among Alpheus species and populations.
The mitochondrial genomic DNA of Alpheus japonicus was obtained by genomic DNA extraction combined with universal primers PCR and long PCR amplification. The complete mitochondrial genome sequence was sequenced using shotgun and primer-walking strategies. Comparative analyses were done combined with A. distinguendus mitochondrial genome, including the basic characteristics, gene order, protein-coding genes, selection pressure, and different sites and so on. The results show that overlapping is found in nine pairs genes of A. japonicus mitochondrial genome. The A. japonicus mitochondrial genome is 16 487 bp in length and is longer than A. distinguendus mitochondrial genome (15 700 bp), mainly due to the length difference of the largest non-coding region. The mitochondrial genomes of A. japonicus and A. distinguendus both contain 37 genes. Gene order of the A. japonicus and A. distinguendus mitochondrial genomes is identical. The translocation of one transfer RNA gene (trnE) involving inversion is found in 2 Alpheus mitochondrial genomes when compared with the pancrustacean ground pattern. There are differences in the usage of start codon and stop codon in protein-coding genes of 2 Alpheus mitochondrial genomes. Except for the cob gene, the numbers of amino acids encoded by the remaining 12 protein-coding genes are identical. The Ka/Ks ratio of all 13 mitochondrial protein coding genes is much lower than 1, indicating a strong negative selection. In 15 major coding genes, nad5 has the largest number of different loci, followed by nad4 and lrRNA genes, can be used as alternative molecular markers to analyze biodiversity among Alpheus species and populations.
2012, 34(5): 154-160.
Abstract:
The priming glycosyltransferase gene (gtf) was cloned from the Antarctic bacterium Pseudoalteromonas sp.S-15-13,which was isolated from sea ice (62°00'S,68°30'E) samples,in order to explore the role and mechanism of extracellular polysaccharides on the low temperature adaptation of this strain.The effects of environmental factors (such as temperature, treatment with freeze-thaw cycles, salt concentrations and pH values) on gtf expression were studied with real-time PCR techniques.It was shown that the gtf expression level of S-15-13 stimulation at 2℃ was about 1.5 times that grown at 10℃ after 1h; and the gtf expression level of S-15-13 grown at 4 and 10℃ was about 8~12 times that grown at 20℃ after 24 h culture; the expression level of gtf was 3.667 times higher than the untreated sample after two freeze-thaw cycles of Pseudoalteromonas sp.S-15-13; 6.0% NaCl could increase the expression level of gtf nearly four times compared to that of 3.0% NaCl, but when the NaCl concentration reached 9.0 %, the expression level of gtf dropped off sharply; pH changes in the range of pH 5.0~8.0 could promote the expression of gtf: the level of gtf expression at pH 6.0 was 2 times that at pH 7.0.Study on gtf of Pseudoalteromonas sp.S-15-13 may have potential to deepen our understanding of the adaptation mechanism of Antarctic bacteria living in harsh environments.
The priming glycosyltransferase gene (gtf) was cloned from the Antarctic bacterium Pseudoalteromonas sp.S-15-13,which was isolated from sea ice (62°00'S,68°30'E) samples,in order to explore the role and mechanism of extracellular polysaccharides on the low temperature adaptation of this strain.The effects of environmental factors (such as temperature, treatment with freeze-thaw cycles, salt concentrations and pH values) on gtf expression were studied with real-time PCR techniques.It was shown that the gtf expression level of S-15-13 stimulation at 2℃ was about 1.5 times that grown at 10℃ after 1h; and the gtf expression level of S-15-13 grown at 4 and 10℃ was about 8~12 times that grown at 20℃ after 24 h culture; the expression level of gtf was 3.667 times higher than the untreated sample after two freeze-thaw cycles of Pseudoalteromonas sp.S-15-13; 6.0% NaCl could increase the expression level of gtf nearly four times compared to that of 3.0% NaCl, but when the NaCl concentration reached 9.0 %, the expression level of gtf dropped off sharply; pH changes in the range of pH 5.0~8.0 could promote the expression of gtf: the level of gtf expression at pH 6.0 was 2 times that at pH 7.0.Study on gtf of Pseudoalteromonas sp.S-15-13 may have potential to deepen our understanding of the adaptation mechanism of Antarctic bacteria living in harsh environments.
2012, 34(5): 161-168.
Abstract:
As one of the most important interfaces of material cycle, energy and species flows between coastal wetlands and adjacent waters, mangrove forest edge is of great scientific importance in understanding the interaction between different ecosystems, biogeomorphogical processes and dynamics of soil organic carbon pool in coastal areas. In order to determine the edge effects and their impact on the soil organic carbon pool, 4 coastal landform types of mangrove distribution area in the east coast of Leizhou Peninsula were selected for investigation. Three subzones of barren flat, forest edge and forest interior were then further indentified in each landform type. The forest structure in the edge and interior, as well as the edaphic physiochemical features for all three subzones were investigated in low tide in August, 2011. Different patterns of vegetation and soil physiochemical indicators were compared among the 4 mangrove landforms. Generally, the edge effect on vegetation was characterized by relatively lower canopy height, leaf area index and species richness in the forest edge than the interior (except the estuarial mangroves). Vegetation coverage decreased with landforms in the forest edge as estuary(QL)> inner bay(TF)> island(TC)> wave hit bench(TJ), coinciding with the degree of wave and storm hit to the areas. The edge effect on soil physicochemical properties in most cases (except TF, the inner bay) showed soil pH, mean grain size in the forest edge were less than that in the barren flat, while redox potential, salinity showed higher on the contrary. But these soil properties in the forest interiors were largely variable among different landforms, since they could be sensitive to the effects of vegetation succession behind the forest edge and microtopography as well. However the SOC (surface soil organic carbon content) and soil organic carbon density increased significantly from the barren flat to the interior in each type of the landforms. Principal component analysis and correlation analysis showed the first principal component, reflecting the joint effect of vegetation cover, leaf area index and soil pH, was negatively correlated with the surface organic carbon density. In other word, despite the variation and strong impact of hydrogeomorphology, organic carbon enrichment in mangrove soil was resulted from the increase of primary production and development of acid edaphic settings.
As one of the most important interfaces of material cycle, energy and species flows between coastal wetlands and adjacent waters, mangrove forest edge is of great scientific importance in understanding the interaction between different ecosystems, biogeomorphogical processes and dynamics of soil organic carbon pool in coastal areas. In order to determine the edge effects and their impact on the soil organic carbon pool, 4 coastal landform types of mangrove distribution area in the east coast of Leizhou Peninsula were selected for investigation. Three subzones of barren flat, forest edge and forest interior were then further indentified in each landform type. The forest structure in the edge and interior, as well as the edaphic physiochemical features for all three subzones were investigated in low tide in August, 2011. Different patterns of vegetation and soil physiochemical indicators were compared among the 4 mangrove landforms. Generally, the edge effect on vegetation was characterized by relatively lower canopy height, leaf area index and species richness in the forest edge than the interior (except the estuarial mangroves). Vegetation coverage decreased with landforms in the forest edge as estuary(QL)> inner bay(TF)> island(TC)> wave hit bench(TJ), coinciding with the degree of wave and storm hit to the areas. The edge effect on soil physicochemical properties in most cases (except TF, the inner bay) showed soil pH, mean grain size in the forest edge were less than that in the barren flat, while redox potential, salinity showed higher on the contrary. But these soil properties in the forest interiors were largely variable among different landforms, since they could be sensitive to the effects of vegetation succession behind the forest edge and microtopography as well. However the SOC (surface soil organic carbon content) and soil organic carbon density increased significantly from the barren flat to the interior in each type of the landforms. Principal component analysis and correlation analysis showed the first principal component, reflecting the joint effect of vegetation cover, leaf area index and soil pH, was negatively correlated with the surface organic carbon density. In other word, despite the variation and strong impact of hydrogeomorphology, organic carbon enrichment in mangrove soil was resulted from the increase of primary production and development of acid edaphic settings.
2012, 34(5): 169-173.
Abstract:
According to chezy formula and two-dimensional suspended sediment diffusion equation, assumed that the vertical diffusion coefficient of sediment is a constant, then a new sediment-carrying capacity formula is derived theoretically.The new sediment-carrying capacity formula not only can be used in general, also applied to high suspended sediment concentration condition.The first-order approximate expression of the formula is coordinated with Liu-formula on its form, which is used in the nearshore frequently.Like Liu-formula, this approximate expression does not contain sediment settling velocity explicitly either.It is proved that the Liu-formula is rational and this empirical formula is reasonable in the theory.For its high-order approximate expression, the new sediment-carrying capacity formula contains sediment settling velocity explicitly, which is coordinated with Velikanov and Zhang's formulae.Therefore, the rationality of Zhang's formula is proved.Analyzed the physical meaning of derived formula and compared it with Liu-formula and Zhang-formula.In addition, the new formula indicated that the approximation of sediment-carrying capacity formula should be multinomial of velocity's second power.There will be some errors if use low order items as its approximate expression.
According to chezy formula and two-dimensional suspended sediment diffusion equation, assumed that the vertical diffusion coefficient of sediment is a constant, then a new sediment-carrying capacity formula is derived theoretically.The new sediment-carrying capacity formula not only can be used in general, also applied to high suspended sediment concentration condition.The first-order approximate expression of the formula is coordinated with Liu-formula on its form, which is used in the nearshore frequently.Like Liu-formula, this approximate expression does not contain sediment settling velocity explicitly either.It is proved that the Liu-formula is rational and this empirical formula is reasonable in the theory.For its high-order approximate expression, the new sediment-carrying capacity formula contains sediment settling velocity explicitly, which is coordinated with Velikanov and Zhang's formulae.Therefore, the rationality of Zhang's formula is proved.Analyzed the physical meaning of derived formula and compared it with Liu-formula and Zhang-formula.In addition, the new formula indicated that the approximation of sediment-carrying capacity formula should be multinomial of velocity's second power.There will be some errors if use low order items as its approximate expression.
2012, 34(5): 174-182.
Abstract:
The wave effect on sediment transport is analyzed in the Bohai Sea area. First, a series of ideal experiments were carried out to investigate the characteristics of wave-current coupled bottom shear stress and the proportion of wave-induced bottom shear stress. Second, a numerical simulation of suspended sediment concentration was compared with the remote sensing data during a gale process in the Bohai Sea. The results indicate that the model output is improved much when the wave-induced bottom shear stress is considered. The wave plays a key role in the resuspension of sediment in the shallow water of 0-20 m depth during the gale weather.
The wave effect on sediment transport is analyzed in the Bohai Sea area. First, a series of ideal experiments were carried out to investigate the characteristics of wave-current coupled bottom shear stress and the proportion of wave-induced bottom shear stress. Second, a numerical simulation of suspended sediment concentration was compared with the remote sensing data during a gale process in the Bohai Sea. The results indicate that the model output is improved much when the wave-induced bottom shear stress is considered. The wave plays a key role in the resuspension of sediment in the shallow water of 0-20 m depth during the gale weather.
2012, 34(5): 183-190.
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2012, 34(5): 191-196.
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2012, 34(5): 197-204.
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2012, 34(5): 205-212.
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2012, 34(5): 213-220.
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2012, 34(5): 221-225.
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