2000 Vol. 22, No. 3
Display Method:
2000, 22(3): 1-6.
Abstract:
It will be valuable to develop a storm surge model which can fits small harbor and Taiwan Strait, especially which involves the flooded areas and interaction of the tide and surge.Taking Xiamen Harbor as its domain area, a model with flooded area, interaction of tide surge and new open boundary condition has been developed.This model indicates a available strategy, which can makes storm surge simulation more accurately in little estuary and bay.
It will be valuable to develop a storm surge model which can fits small harbor and Taiwan Strait, especially which involves the flooded areas and interaction of the tide and surge.Taking Xiamen Harbor as its domain area, a model with flooded area, interaction of tide surge and new open boundary condition has been developed.This model indicates a available strategy, which can makes storm surge simulation more accurately in little estuary and bay.
2000, 22(3): 7-14.
Abstract:
According to a three-dimensional baroclinic shelf sea model's numerical simulation results, the seasonal variation of the South China Sea(SCS)upper mixed layer is revealed.It is shown that: (1)In the northern SCS, the variation of the upper mixed layer depth(i.e.,the depth of the lower limit of mixed layer)is distinctly seasonal, which is different to that in the southern SCS, and the strength variation range of mixed layer is larger in the northern SCS.(2) In the western boundary area along the east offshore of middle Indo-China Peninsular, due to the control of cold eddy, the lower cold water upwells, and the upper layer water stratifys distinctly, which makes the vertical mixing weakened.(3) In the peripheries of some cyclonic(anticyclonic) eddies, the distribution of mixed layer depth isobath is dense and its horizontal gradient is large.(4) There is a good relation of geostrophic adjustment between the distribution characteristic of upper mixed layer and the pattern of upper circulation in the SCS.
According to a three-dimensional baroclinic shelf sea model's numerical simulation results, the seasonal variation of the South China Sea(SCS)upper mixed layer is revealed.It is shown that: (1)In the northern SCS, the variation of the upper mixed layer depth(i.e.,the depth of the lower limit of mixed layer)is distinctly seasonal, which is different to that in the southern SCS, and the strength variation range of mixed layer is larger in the northern SCS.(2) In the western boundary area along the east offshore of middle Indo-China Peninsular, due to the control of cold eddy, the lower cold water upwells, and the upper layer water stratifys distinctly, which makes the vertical mixing weakened.(3) In the peripheries of some cyclonic(anticyclonic) eddies, the distribution of mixed layer depth isobath is dense and its horizontal gradient is large.(4) There is a good relation of geostrophic adjustment between the distribution characteristic of upper mixed layer and the pattern of upper circulation in the SCS.
2000, 22(3): 15-19.
Abstract:
The Hessian matrix, which is formed by the second order partial derivatives of the cost function with respect to control variables, plays an important role in the procedure of variational data assimilation(VDA), sensitivity analysis, etc.,and it can be obtained by establishing the first order adjoint(FOA) and second order adjoint (SOA) models for direct model.The derivations of the FOA and SOA models of shallow water equations model are given in detail, which is based upon the Gateaux differential of functional and the concepts of the adjoint operators in Hilbert space.We obtain the result for SOA model of the shallow water equations model, which improves the theory established in the paper of Zhi Wang et al.(1992).
The Hessian matrix, which is formed by the second order partial derivatives of the cost function with respect to control variables, plays an important role in the procedure of variational data assimilation(VDA), sensitivity analysis, etc.,and it can be obtained by establishing the first order adjoint(FOA) and second order adjoint (SOA) models for direct model.The derivations of the FOA and SOA models of shallow water equations model are given in detail, which is based upon the Gateaux differential of functional and the concepts of the adjoint operators in Hilbert space.We obtain the result for SOA model of the shallow water equations model, which improves the theory established in the paper of Zhi Wang et al.(1992).
2000, 22(3): 20-33.
Abstract:
By improving a six-layer global ocean model with a resolution of 5°×4°, we have established a ten-layer global ocean model with the same resolution and simulated the seasonal variation of global ocean.After a 250 year integration, an equilibrium state of ocean was reached.The simulated seasonal variation is similar to that of observed except for ocean in high latitude.Then we took the results at the end of seasonal variation as the initial state for a series of sensitive experiments.On the basis of these work mentioned above, we have done three kinds of windstress anomaly sensitive experiments on the response of sea temperature in tropical Pacific to anomaly of tropical monsoon.First kind of sensitive experiment is involved in anomalous westerly propagating eastwards over equatorial western Pacific; second is an experiment on anomaly of windstress oscillation over the whole equatorial Pacific, and third experiment is made on alternating between anomalous westerly propagating eastwards and anomalous easterly propagating eastwards over equatorial western Pacific.The simulation results of three kinds of sensitive experiments show as follows.(a) Sea temperature's warming in eastern Pacific similar to El Niño event can be reproduced by westerly windstress anomaly propagating eastwards in western Pacific in first kind of windstress anomaly sensitive experiment.(b) In second kind of experiment, sea temperature anomaly was first stimulated in east and west part of tentral Pacific respectively by local oscillation of windstress in tropical Pacific, then propagated eastwards and westwards to eastern Pacific and western Pacific respectively.As a result sea temperature anomaly emerged at equatorial eastern Pacific and western Pacific.(c) The third kind of experiment have shown that QBO of windstress can motivate oscillation of ocean similar to QBO.
By improving a six-layer global ocean model with a resolution of 5°×4°, we have established a ten-layer global ocean model with the same resolution and simulated the seasonal variation of global ocean.After a 250 year integration, an equilibrium state of ocean was reached.The simulated seasonal variation is similar to that of observed except for ocean in high latitude.Then we took the results at the end of seasonal variation as the initial state for a series of sensitive experiments.On the basis of these work mentioned above, we have done three kinds of windstress anomaly sensitive experiments on the response of sea temperature in tropical Pacific to anomaly of tropical monsoon.First kind of sensitive experiment is involved in anomalous westerly propagating eastwards over equatorial western Pacific; second is an experiment on anomaly of windstress oscillation over the whole equatorial Pacific, and third experiment is made on alternating between anomalous westerly propagating eastwards and anomalous easterly propagating eastwards over equatorial western Pacific.The simulation results of three kinds of sensitive experiments show as follows.(a) Sea temperature's warming in eastern Pacific similar to El Niño event can be reproduced by westerly windstress anomaly propagating eastwards in western Pacific in first kind of windstress anomaly sensitive experiment.(b) In second kind of experiment, sea temperature anomaly was first stimulated in east and west part of tentral Pacific respectively by local oscillation of windstress in tropical Pacific, then propagated eastwards and westwards to eastern Pacific and western Pacific respectively.As a result sea temperature anomaly emerged at equatorial eastern Pacific and western Pacific.(c) The third kind of experiment have shown that QBO of windstress can motivate oscillation of ocean similar to QBO.
2000, 22(3): 34-43.
Abstract:
The interannual and interdecadal variation in SST over Indian-Pacific Ocean for recent 50 years was investigated in term of EOF method.Then the numerical experiment was made based on the result of above diagnosis.The results display that the EOFl of SST shows interdecadal variation with two sudden climate changing in 1956 and 1976, the EOF2 correspond to ENSO events.The precipitation variation over the east part of China and Asian summer monsoon anomaly are affected not only by ENSO events but also by the interdecadal background of SST.The results of diagnosis and numerical experiment are better similar each other.
The interannual and interdecadal variation in SST over Indian-Pacific Ocean for recent 50 years was investigated in term of EOF method.Then the numerical experiment was made based on the result of above diagnosis.The results display that the EOFl of SST shows interdecadal variation with two sudden climate changing in 1956 and 1976, the EOF2 correspond to ENSO events.The precipitation variation over the east part of China and Asian summer monsoon anomaly are affected not only by ENSO events but also by the interdecadal background of SST.The results of diagnosis and numerical experiment are better similar each other.
2000, 22(3): 44-48.
Abstract:
To improve the accuracy of numerical modeling of 3-dimensional (3-D) wave transformation by boundary element method (BEM),based on the formation of constant and linear element, a new model (0-1 combined type BEM) is developed.By means of this model, the "transverse oscillation" caused by the accumulation of errors during the calculation can be suppressed.Using this and combining with sub-domain of BEM, the calculation of linear wave transformation in a large area can be done.This method can also be used for the nonlinear wave transformation in time domain.
To improve the accuracy of numerical modeling of 3-dimensional (3-D) wave transformation by boundary element method (BEM),based on the formation of constant and linear element, a new model (0-1 combined type BEM) is developed.By means of this model, the "transverse oscillation" caused by the accumulation of errors during the calculation can be suppressed.Using this and combining with sub-domain of BEM, the calculation of linear wave transformation in a large area can be done.This method can also be used for the nonlinear wave transformation in time domain.
2000, 22(3): 49-54.
Abstract:
The membrane lipid peroxidation of the leaves of mangrove Kandelia candel seedling to long- and short-term salinity is dealt with.There were different trends in the SOD activity, MDA concentration and succulence of K.candel leaf with increasing salinity between long-term salt-stress (45 d) and short-term salt-stress(1 d).At short-term salt-stress with increasing salinity, SOD activity appeared in U-shaped, minimized at salinity 15~20;MDA concentration did not change significantly, electrolyte leakage(%)increased, and leaf succulence increased at first, maximized at salinity 20, then declined.While at long-term salt-stress with increasing salinity, SOD activity increased at low salinity and decreased at higher salinity, MDA concentration declined, electrolyte leakage and leaf succulence increased.There were differences in salt-tolerant mechanism between long-term saltstressed group and short-term salt-stressed group.Membrane lipid peroxidation was not the main reason for the destroy of K.candel leaves under salt stress.
The membrane lipid peroxidation of the leaves of mangrove Kandelia candel seedling to long- and short-term salinity is dealt with.There were different trends in the SOD activity, MDA concentration and succulence of K.candel leaf with increasing salinity between long-term salt-stress (45 d) and short-term salt-stress(1 d).At short-term salt-stress with increasing salinity, SOD activity appeared in U-shaped, minimized at salinity 15~20;MDA concentration did not change significantly, electrolyte leakage(%)increased, and leaf succulence increased at first, maximized at salinity 20, then declined.While at long-term salt-stress with increasing salinity, SOD activity increased at low salinity and decreased at higher salinity, MDA concentration declined, electrolyte leakage and leaf succulence increased.There were differences in salt-tolerant mechanism between long-term saltstressed group and short-term salt-stressed group.Membrane lipid peroxidation was not the main reason for the destroy of K.candel leaves under salt stress.
2000, 22(3): 55-60.
Abstract:
While the area of the Nandu River Delta in Hainan Island of China is only 120 km2, the abandoned part accounts for 80 km2.According to carbon-14 dating data, stratigraphic facies, and old barrier island analysis results, it is shown that the Nandu River Delta developed from the south to the north toward the Qiongzhou Strait during the period of 4 000~8 000 a BP, and that it developed from the east to the west toward the Haikou Bay during the period of 2 000~4 000 a BP.The deposit center of the delta was diverted toward the Haikou Bay, and the eastern part of the delta was abandoned due to the operation of the prevailing northeast wave.The geomorphic characteristics of the abandoned delta: linear transgressive shore, marsh mud on the beach face, a set of abandoned, semi-abandoned and active river mouths displayed from the east to the west, etc.,are present.Erosion is very obvious in the active delta front.The erosive rate of the shoreline is about 8~10 m/a.The linear scarp along 10 m depth curve was cut by the strait tidal current and the sediment was transported to the east.The northeastern part of the subaquatic delta of the Nandu River mouth was cut by the northeast wave and the sediment was transported to the west and shoreward.
While the area of the Nandu River Delta in Hainan Island of China is only 120 km2, the abandoned part accounts for 80 km2.According to carbon-14 dating data, stratigraphic facies, and old barrier island analysis results, it is shown that the Nandu River Delta developed from the south to the north toward the Qiongzhou Strait during the period of 4 000~8 000 a BP, and that it developed from the east to the west toward the Haikou Bay during the period of 2 000~4 000 a BP.The deposit center of the delta was diverted toward the Haikou Bay, and the eastern part of the delta was abandoned due to the operation of the prevailing northeast wave.The geomorphic characteristics of the abandoned delta: linear transgressive shore, marsh mud on the beach face, a set of abandoned, semi-abandoned and active river mouths displayed from the east to the west, etc.,are present.Erosion is very obvious in the active delta front.The erosive rate of the shoreline is about 8~10 m/a.The linear scarp along 10 m depth curve was cut by the strait tidal current and the sediment was transported to the east.The northeastern part of the subaquatic delta of the Nandu River mouth was cut by the northeast wave and the sediment was transported to the west and shoreward.
2000, 22(3): 61-66.
Abstract:
The study samples were collected from the central Okinawa Trough during R/V Xiangyanghong No.16 cruise on June to July 1992.The geochemical data of the surface sediments of the central Okinawa Trough are studied by factor analysis and typical components' correlation analysis.The results show that the surface sediments of the central Okinawa Trough are basically made up of terrestrial source, biological source and volcanic and hydrothermal source components.The results of revised EF indicate that terrestrial source, biological source and volcanic and hydrothermal source components vary from area to area.
The study samples were collected from the central Okinawa Trough during R/V Xiangyanghong No.16 cruise on June to July 1992.The geochemical data of the surface sediments of the central Okinawa Trough are studied by factor analysis and typical components' correlation analysis.The results show that the surface sediments of the central Okinawa Trough are basically made up of terrestrial source, biological source and volcanic and hydrothermal source components.The results of revised EF indicate that terrestrial source, biological source and volcanic and hydrothermal source components vary from area to area.
2000, 22(3): 67-73.
Abstract:
The species and diversity of ecological groups of planktonic Ostracoda in the waters of the southern East China Sea and the eastern waters off Taiwan Island are analyzed, the seasonal difference and regional variation are also expounded.The results show that there are four ecological groups in this sea area but the hyperthermal and hyperhaline group plays the predominant role.Meanwhile, there is a distinct difference in the abundance of planktonic Ostracoda in summer and winter, the average values are 0.63 and 1.22 ind./m3 in July and December respectively.As regarding to the horizontal distribution, its tendency exhibits that the individual density in the waters of the southern East China Sea is higher than that in the eastern waters off Taiwan Island, and a higher concentrated area is formed in the northeast part of this sea area.The community structure in this sea area was emphatically expounded.There are three ecological groups in this sea area but the off-lying community occupies the most part of the sea area.It should be specially noted that all the communities either in the vicinity of waters of Diaoyu Island or in the northern and eastern waters off Taiwan Island are the common off-lying community.In addition, the seasonal migration of the geographical position of the community habitat resulted from the changes of environmental elements in this waters is also analyzed.
The species and diversity of ecological groups of planktonic Ostracoda in the waters of the southern East China Sea and the eastern waters off Taiwan Island are analyzed, the seasonal difference and regional variation are also expounded.The results show that there are four ecological groups in this sea area but the hyperthermal and hyperhaline group plays the predominant role.Meanwhile, there is a distinct difference in the abundance of planktonic Ostracoda in summer and winter, the average values are 0.63 and 1.22 ind./m3 in July and December respectively.As regarding to the horizontal distribution, its tendency exhibits that the individual density in the waters of the southern East China Sea is higher than that in the eastern waters off Taiwan Island, and a higher concentrated area is formed in the northeast part of this sea area.The community structure in this sea area was emphatically expounded.There are three ecological groups in this sea area but the off-lying community occupies the most part of the sea area.It should be specially noted that all the communities either in the vicinity of waters of Diaoyu Island or in the northern and eastern waters off Taiwan Island are the common off-lying community.In addition, the seasonal migration of the geographical position of the community habitat resulted from the changes of environmental elements in this waters is also analyzed.
2000, 22(3): 74-85.
Abstract:
Some prediction models that can be used to predict sheet ice forces acting on conical structures are introduced.An assessment is made to compare several representative prediction models with experimental measurements for sheet ice forces on conical structures.Differences among the models are identified.Statistic measurements of these models are provided so that the uncertainty of accuracy for each of the models can be quantified.This method can be used for comparison in-situ observation on platform JZ20-2 with the prediction models, and the statistic results are necessary for the analysis of the structure reliabilitv.
Some prediction models that can be used to predict sheet ice forces acting on conical structures are introduced.An assessment is made to compare several representative prediction models with experimental measurements for sheet ice forces on conical structures.Differences among the models are identified.Statistic measurements of these models are provided so that the uncertainty of accuracy for each of the models can be quantified.This method can be used for comparison in-situ observation on platform JZ20-2 with the prediction models, and the statistic results are necessary for the analysis of the structure reliabilitv.
2000, 22(3): 86-93.
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2000, 22(3): 103-109.
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2000, 22(3): 110-116.
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2000, 22(3): 117-122.
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2000, 22(3): 123-131.
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2000, 22(3): 132-136.
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2000, 22(3): 137-143.
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2000, 22(3): 144-148.
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