1998 Vol. 17, No. 1
Display Method:
1998, (1): 1-13.
Abstract:
On the basis of hydrographic data obtained during two October cruises of 1995, a modified inverse method is used to compute the Kuroshio east of Taiwan and the currents east of the Ryukyu-gunto.The net northward volume transport(VT) of the Kuroshio through Section TK2-K2 southeast of Taiwan is about 57.8×106 m3/s.There are four current cores of the Kuroshio at Section TK2-K2.Its main core is near the south of Taiwan, and its maximum speed is about 257 cm/s at the surface.After the Kuroshio flows through Section TK2-K2, there are three branches of the Kuroshio.The main branch of the Kuroshio flows northward into Section TKa east of Su'ao.The second branch of the Kuroshio flows northward through Section TKa and then enters the East China Sea through the region between Yonakunijima and Iriomote-shima.The net northward VT of the Kuroshio through Section TK4 is about 21.6×106 m3/s.The eastern branch of the Kuroshio flows northeastward through the region between a stronger cyclonic eddy and a recirculating anticyclonic gyre, and then flows continuously northeastward to the region east of the Ryūkyū-guntō and becomes a part of the origin of the western boundary current east of the Ryūkyū-guntō.Another part of the origin of the western boundary current east of the Ryūkyū-guntō comes from a recirculating anticyclonic gyre.From the above, in the regions east of Taiwan end east of the Ryūkyū-guntō the pattern of circulation during October of 1995 differs from the pattern of circulation during early summer of 1985.There are several eddies of different scales in this computational region.For example, there is a meso-scale stronger cyclonic eddy whose center is located at about 23°N, 124°20'E.
On the basis of hydrographic data obtained during two October cruises of 1995, a modified inverse method is used to compute the Kuroshio east of Taiwan and the currents east of the Ryukyu-gunto.The net northward volume transport(VT) of the Kuroshio through Section TK2-K2 southeast of Taiwan is about 57.8×106 m3/s.There are four current cores of the Kuroshio at Section TK2-K2.Its main core is near the south of Taiwan, and its maximum speed is about 257 cm/s at the surface.After the Kuroshio flows through Section TK2-K2, there are three branches of the Kuroshio.The main branch of the Kuroshio flows northward into Section TKa east of Su'ao.The second branch of the Kuroshio flows northward through Section TKa and then enters the East China Sea through the region between Yonakunijima and Iriomote-shima.The net northward VT of the Kuroshio through Section TK4 is about 21.6×106 m3/s.The eastern branch of the Kuroshio flows northeastward through the region between a stronger cyclonic eddy and a recirculating anticyclonic gyre, and then flows continuously northeastward to the region east of the Ryūkyū-guntō and becomes a part of the origin of the western boundary current east of the Ryūkyū-guntō.Another part of the origin of the western boundary current east of the Ryūkyū-guntō comes from a recirculating anticyclonic gyre.From the above, in the regions east of Taiwan end east of the Ryūkyū-guntō the pattern of circulation during October of 1995 differs from the pattern of circulation during early summer of 1985.There are several eddies of different scales in this computational region.For example, there is a meso-scale stronger cyclonic eddy whose center is located at about 23°N, 124°20'E.
1998, (1): 15-25.
Abstract:
The M2 constituent in the coastal areas of the East China Sea is computed based on three-dimensional nonlinear tidal wave equations.The distributions of the tide-induced horizontal residual currents and the tide-induced vertical residual currents indicate that there exists a coastal upwelling stripe off Fujian and Zhejiang with a width of 40 km or so.The computed largest upwelling, 0.5×10-3 cm/s, occurs between 10 and 20 m levels.
The M2 constituent in the coastal areas of the East China Sea is computed based on three-dimensional nonlinear tidal wave equations.The distributions of the tide-induced horizontal residual currents and the tide-induced vertical residual currents indicate that there exists a coastal upwelling stripe off Fujian and Zhejiang with a width of 40 km or so.The computed largest upwelling, 0.5×10-3 cm/s, occurs between 10 and 20 m levels.
1998, (1): 27-39.
Abstract:
Utilizing the historical tide-gauge records (1912-1993) and the statistical approaches, two issues, the characteristics of the mean annual eustatic sea level (MAESL) in the last decades and its long-term amplitude's estimation in the coming years for Shanghai are dealt with in this paper.
A statistical method fitting the variation of the MAESL is established.It is shown from the model extrapolation that the MAESL will rise by 5 and 11 cm, respectively relative to 1990 for Shanghai by the years of 2010 and 2030.As to the current ground subsidence mainly resulting from the over-exploitation of ground water and the average vertical crust deformation and its trend, it is estimated by other Chinese scientists that ground subsides by 12 and 19 cm on average, respectively.
Considering a variety of undeterminable factors in mean annual relative sea-level estimation, the reasonable values of the mean rate of rise in the relative sea-level relative to 1990 for Shanghai roughly amount to be 15-25 cm in 2010 and 25-35 cm in 2030.
Finally the reasons for the rising of the mean sea-level of Shanghai are tentatively discussed.
Utilizing the historical tide-gauge records (1912-1993) and the statistical approaches, two issues, the characteristics of the mean annual eustatic sea level (MAESL) in the last decades and its long-term amplitude's estimation in the coming years for Shanghai are dealt with in this paper.
A statistical method fitting the variation of the MAESL is established.It is shown from the model extrapolation that the MAESL will rise by 5 and 11 cm, respectively relative to 1990 for Shanghai by the years of 2010 and 2030.As to the current ground subsidence mainly resulting from the over-exploitation of ground water and the average vertical crust deformation and its trend, it is estimated by other Chinese scientists that ground subsides by 12 and 19 cm on average, respectively.
Considering a variety of undeterminable factors in mean annual relative sea-level estimation, the reasonable values of the mean rate of rise in the relative sea-level relative to 1990 for Shanghai roughly amount to be 15-25 cm in 2010 and 25-35 cm in 2030.
Finally the reasons for the rising of the mean sea-level of Shanghai are tentatively discussed.
1998, (1): 41-52.
Abstract:
Firstly, this paper iVustrates the global structure of the sea surface temperature (SST) anomalies associated with El Nino and El Niño events and the Southern Oscillation (SO) structure associated with the sea level pressure (SLP) anomaly.Secondly the typical structure of the SO forced by global ocean heat source and real topography was simulated by using of IAP two-level atmospheric general circulation model.The simulated location of the SLP anomaly centers over the eastern Pacific differs significantly with the observations if only the SST heat source without topography was considered.It suggests that the SO may be a response to the global SST anomaly under the real topography.
Firstly, this paper iVustrates the global structure of the sea surface temperature (SST) anomalies associated with El Nino and El Niño events and the Southern Oscillation (SO) structure associated with the sea level pressure (SLP) anomaly.Secondly the typical structure of the SO forced by global ocean heat source and real topography was simulated by using of IAP two-level atmospheric general circulation model.The simulated location of the SLP anomaly centers over the eastern Pacific differs significantly with the observations if only the SST heat source without topography was considered.It suggests that the SO may be a response to the global SST anomaly under the real topography.
1998, (1): 53-61.
Abstract:
SSM/I data on the Bohai Sea of China from 1994 to 1996 have been studied.The sea ice algorithms of calibration/validation such as the brightness temperature index[AES/YORK TBI (Hollinger et al.,1992)] and ocean scattering index[OSI (Ferraro et al.,1996, The Bulletin of the American Meteorological Society, 77(5), 891-905)] are not applicable to the detection of regional sea ice of mid-latitude Bohai area.This paper presents a method of the scatfeting index SI and polarization index PI to identify regional Bohai Sea ice.Numerical results of vector radiative transfer for a model of a layer of sea ice over ocean simulate the relationship between SI/PI and sea ice depth, and others.It is employed to categorize the SI/PI indexes for the detection of sea ice.
SSM/I data on the Bohai Sea of China from 1994 to 1996 have been studied.The sea ice algorithms of calibration/validation such as the brightness temperature index[AES/YORK TBI (Hollinger et al.,1992)] and ocean scattering index[OSI (Ferraro et al.,1996, The Bulletin of the American Meteorological Society, 77(5), 891-905)] are not applicable to the detection of regional sea ice of mid-latitude Bohai area.This paper presents a method of the scatfeting index SI and polarization index PI to identify regional Bohai Sea ice.Numerical results of vector radiative transfer for a model of a layer of sea ice over ocean simulate the relationship between SI/PI and sea ice depth, and others.It is employed to categorize the SI/PI indexes for the detection of sea ice.
1998, (1): 63-70.
Abstract:
Through the water areas extracted from remote sensing images and the combination of the methods for establishing the formula for calculating tidal influx with tidal data, the tidal influx of the Haikou Bay, Hainan Province was found to be 5.14×107m3 in 1990, 5.80×107m3 in 1984 and 5.05×107m3 in 1965, respectively.After the analysis of the morphological and tidal range factors which determine tidal influx, this paper presents the trend of the changes in tidal influx caused by the changes in the morphological factors of the Haikou Bay.It is found that a decreasing trend was shown with a depressive rate of 2×10-3during the period from 1965 to 1984, and an increasing trend with an incremental rate of 1×10-3 during the period of 1984-1990.The main reason for the appearance of the decreasing trend before 1984 is the natural deposition and silting-up of the bay sediments; after 1984, the dredging and expansion of the Haikou Port and the Haikou New Port which caused an increase in water area at the mean low tide are the leading factor which causes the increase in tidal influx.
Through the water areas extracted from remote sensing images and the combination of the methods for establishing the formula for calculating tidal influx with tidal data, the tidal influx of the Haikou Bay, Hainan Province was found to be 5.14×107m3 in 1990, 5.80×107m3 in 1984 and 5.05×107m3 in 1965, respectively.After the analysis of the morphological and tidal range factors which determine tidal influx, this paper presents the trend of the changes in tidal influx caused by the changes in the morphological factors of the Haikou Bay.It is found that a decreasing trend was shown with a depressive rate of 2×10-3during the period from 1965 to 1984, and an increasing trend with an incremental rate of 1×10-3 during the period of 1984-1990.The main reason for the appearance of the decreasing trend before 1984 is the natural deposition and silting-up of the bay sediments; after 1984, the dredging and expansion of the Haikou Port and the Haikou New Port which caused an increase in water area at the mean low tide are the leading factor which causes the increase in tidal influx.
1998, (1): 71-83.
Abstract:
The distribution of the abundance of phytoplankton, chlorophyll a (Chl.a) concentration and primary productivity in the Beibu Gulf were observed from May 23 to June 4, 1994.The results show that there were marked featares of spatial zonation in the survey area due to the differences between the geographic environment and the hydrological conditions.Chlorophyll a and primary productivity were higher in the inshore than in the middle area and higher in the north than in the south of the Beibu Gulf.The average concentration of Chl.a, primary productivity and the abundance of phytoplankton were 0.94±0.45 μg/dm3, 351±172 mg/(m2·d) (C) and 0.97×104-10.050×104 ind./m3 in the area, respectively.There were 176 species belonging to 4 phyla and 56 genera based on microscope identification.The results of the size-fractionation show that the contribution of nanoplankton and picoplankton was 77% to total Chl.a and 91% to total primary productivity, which proved their importance to phytoplankton communities in the Beibu Gulf.
The distribution of the abundance of phytoplankton, chlorophyll a (Chl.a) concentration and primary productivity in the Beibu Gulf were observed from May 23 to June 4, 1994.The results show that there were marked featares of spatial zonation in the survey area due to the differences between the geographic environment and the hydrological conditions.Chlorophyll a and primary productivity were higher in the inshore than in the middle area and higher in the north than in the south of the Beibu Gulf.The average concentration of Chl.a, primary productivity and the abundance of phytoplankton were 0.94±0.45 μg/dm3, 351±172 mg/(m2·d) (C) and 0.97×104-10.050×104 ind./m3 in the area, respectively.There were 176 species belonging to 4 phyla and 56 genera based on microscope identification.The results of the size-fractionation show that the contribution of nanoplankton and picoplankton was 77% to total Chl.a and 91% to total primary productivity, which proved their importance to phytoplankton communities in the Beibu Gulf.
1998, (1): 85-95.
Abstract:
The three-dimensional water quality model has been developed to simulate the variations in water quality and the ecosystem in the harbour.The model is unique in that it completely integrates the refined modelling of the hydrodynamics, biochemical reactions and the ecosystem in the harbour.It is a 3-dimensional segmented model which is capable of resolving mean daily variations in all the parameters relevant to pollution control.It predicts daily fluctuations in the oxygen content at different depths in water throughout the year.It takes into account transport and settling of poVutant partities.It predicts light penetration from computed turbidity variations.It includes interactions between the ecosystem and water quality, through nutrient cycling and photosynthesis.The model has been calibrated well against the historical data set of water quality observations.
The three-dimensional water quality model has been developed to simulate the variations in water quality and the ecosystem in the harbour.The model is unique in that it completely integrates the refined modelling of the hydrodynamics, biochemical reactions and the ecosystem in the harbour.It is a 3-dimensional segmented model which is capable of resolving mean daily variations in all the parameters relevant to pollution control.It predicts daily fluctuations in the oxygen content at different depths in water throughout the year.It takes into account transport and settling of poVutant partities.It predicts light penetration from computed turbidity variations.It includes interactions between the ecosystem and water quality, through nutrient cycling and photosynthesis.The model has been calibrated well against the historical data set of water quality observations.
1998, (1): 97-112.
Abstract:
In shallow mixed waters, light intensity, transparency, water temperature, salinity and Chl a concentration are measured throughout the year, as well as variation of light intensity and Chl a over the course of the day.Primary productivity in these waters is determined with a P-I model and the conventional method at the same time.The results show that the vertical profile of phytoplankton and Chl a in the shallow mixed waters is even, the P-I model method can estimate primary productivity of the water body more accurately.Being calibrated, the biases from the conventional method can be reduced greatly.In this paper, primary productivity in the shallow mixed wates along the coast of Shandong Province determined with the conventional method is corrected from the developed P-I model.
In shallow mixed waters, light intensity, transparency, water temperature, salinity and Chl a concentration are measured throughout the year, as well as variation of light intensity and Chl a over the course of the day.Primary productivity in these waters is determined with a P-I model and the conventional method at the same time.The results show that the vertical profile of phytoplankton and Chl a in the shallow mixed waters is even, the P-I model method can estimate primary productivity of the water body more accurately.Being calibrated, the biases from the conventional method can be reduced greatly.In this paper, primary productivity in the shallow mixed wates along the coast of Shandong Province determined with the conventional method is corrected from the developed P-I model.
1998, (1): 113-119.
Abstract:
In February and March 1993, the R/V Xiangyanghong 5 collected 19 eggs of the Japanese eel Anguilla japonica in a survey cruise of the spawning site of Anguilla japonica in the waters adjacent to the North Equatorial Current.The discovery marks an important contribution to further defining the spawning site of Anguilla japonica for the first time by China in the waters adjacent to the North Equatorial Current.This paper presents en analysis of the investigation results during the cruise and a morphological description of the eggs of the Japanese eel collected.
In February and March 1993, the R/V Xiangyanghong 5 collected 19 eggs of the Japanese eel Anguilla japonica in a survey cruise of the spawning site of Anguilla japonica in the waters adjacent to the North Equatorial Current.The discovery marks an important contribution to further defining the spawning site of Anguilla japonica for the first time by China in the waters adjacent to the North Equatorial Current.This paper presents en analysis of the investigation results during the cruise and a morphological description of the eggs of the Japanese eel collected.
1998, (1): 121-132.
Abstract:
A wave breaking model is proposed on the basis of turbulent energy equation and the relationship of energy dissipation due to wave breaking en the surf zone.The model is established by introducing turbulent dissipation terms into the Iioussinesq equations and involves the breaking process of individual wave.The model is verified by experiment data in terms of wave height and mean surface elevation.Good agreements are obtained.
A wave breaking model is proposed on the basis of turbulent energy equation and the relationship of energy dissipation due to wave breaking en the surf zone.The model is established by introducing turbulent dissipation terms into the Iioussinesq equations and involves the breaking process of individual wave.The model is verified by experiment data in terms of wave height and mean surface elevation.Good agreements are obtained.
1998, (1): 133-139.
Abstract:
