1990 Vol. 9, No. 1

Physical Oceanography,Marine Meteorology and Marine Physics
The equilibrium range of wind wave frequency spectrum
Wen Shengchang(S. C. Wen), Zhang Dacuo, Chen Bohai, Guo Peifang
1990, (1): 1-11.
Abstract:
Theoretical form of equilibrium range is given on the basis of the wind wave frequency spectra proposed by Wenel al.(1988a,b,c, 1989a,b).The effects of peakness factor and water depth are discussed.In the case of deep water the e-quilibrium range is reduced to the form first proposed by Toba (1973) and the coefficient of the formula is shown to be the function of nondimensional fetch or peak frequency.Results of the present paper have been verified through field data.
Combined refraction and diffraction models for sea waves over complicated topography and with currents in shallow water
Yin Baoshu, Jiang Decai
1990, (1): 13-23.
Abstract:
Combined refraction and diffraction models in the form of linear parabolic approximation are derived through smallparameter method.More strictly theoretical basis and more accuracy in the models than Lozano's (1980) are obtained.Some theoretical defects in Liu's model (1985) with consideration of current are not only found but also eliminated.More strict and accurate models are, therefore, presented in this paper.
The calculation results and analysis in applying the models to actual wave field with consideration of bottom friction will be given in the following paper.
Seasonal responses of monthly mean sea levels in the Bohai Sea to hydrometeorological forcing and their double screening regression models
Chen Shangji, Ma Jirui, Yu Jiye
1990, (1): 25-35.
Abstract:
In this paper, the maximum entropy spectral, the cross-spectral and the frequency response analyses are madeon the basis of the data of monthly mean sea levels at coastal stations in the Bohai Sea during 1965-1986.The results show that the annual fluctuations of the monthly mean sea levels in the Bohai Sea are the results of the coupling response of seasonal variations of the marine hydrometeorological factors.Furthermore, the regression prediction equation is obtained by using the double screening stepwise regression analysis method.Through the prediction test, it is proved that the obtained results are desirable.
Nonlinear tidal waves in a kind of estuary with gradually varying cross-section
Du Yong, Chen Zongyong, Ye Anle
1990, (1): 37-50.
Abstract:
Nonlinear tidal waves in a kind of estuary are studied in the paper using one-dimensional nonlinear hydrody-namic equations with friction.The estuary has exponentially varying width B=B0e-bx and uniform depth h.The one-dimensional hydrodynamic equations are solved by perturbation method.It was found that our solution included two special cases, Pelisenpeki's solution and Airy's solution.The former can be got by letting b=0 in our solutions, and the latter by setting b=0 and f=0 (f is linear frictional coefficient).In terms of the second-order solution, the physical mechanism of nonlinear tidal waves in estuaries with gradually varying cross-section is explored.It is shown that, under the assumption of linear friction coefficient, shallow water constituent waves consist of two parts, one is produced by shallow water nonlinear effect outside the estuary, the other is generated by shallow water nonlinear effect inside estuary.In addition, the physical mechanism of the residual tidal current and elevation are not exactly the same as that of the shallow water constituent waves. The former results from the interaction of shallow water nonlinear effect, friction and estuarine deforming effect.The latter depends chiefly on shallow water nonlinear effect. Finally, present nonlinear model is applied to the modelling of the tidal waves in the Hangzhou Bay.Seven of constituent waves (O1, K1,M2, S2, M4,S4, MS4) are taken into account. It will be found that the results modelled by incident progressive waves and their Interaction agree rather well with the observations, therefore, it can be concluded that the incident progressive waves in the Hangzhou Bay are dominant.
Marine Meteorology
The numerical criteria and characteristics of El Nino and La Nina
Wang Shiping
1990, (1): 51-59.
Abstract:
By using the sea surface temperature (SST) index of the Equatorial Pacific Ocean provided by Climate Analysis Center of U.S.A., the numerical criteria of El Nino and La Nina events and their quantitative characteristics were calculated.Results show that the El Nino event was characterized with strong intensity, shorter life cycle and significant mature phase; however, the La Nina event has longer live cycle, weak intensity, insignificant mature phase.Through teleconnection analysis, it is found that the intensity index of SST over the Equatorial Pacific Ocean leads the intensity index of subtropical high by six months or so.During the El Nino years, the tropical cyclone over the northwestern Pacific is fewer than normal but stronger, and its genesis area shifts southeastward apparently; while in the La Nina years the number of tropical cyclones are larger.
Threshold autoregression models for forecasting El Nino events
Pu Shuzhen, Yu Huiling
1990, (1): 61-67.
Abstract:
In this paper, monthly mean SST data in a large area are used.After the spacial average of the data is carried out and the secular monthly means are substracted, a time series (Jan.1951-Dec.1985) of SST anomalies of the cold tongue water area in the eastern tropical Pacific Ocean is obtained.On the basis of the time series, an autoregression model, a self-exciting threshold autoregression model and an open loop autoregression model are developed respectively.The interannual variations are simulated by means of those models.The simulation results show that all the three models have made very good hindcasting for the nine El Nino events since 1951.In order to test the reliability of the open loop threshold model, extrapolated forecast was made for the period of Jan.1986-Feb.1987.It can be seen from the forecasting that the model could forecast well the beginning and strengthening stages of the recent El Nino event (1986-1987).Correlation coefficients of the estimations to observations are respectively 0.89,0.88 and 0.89. It is obvious that all the models work well and the open loop threshold one is the best.So the open loop threshold autoregression model is a useful tool for monitoring the SST interannual variation of the cold tongue water area in the Eastern Equatorial Pacific Ocean and for estimating the El Nino strength.
The computation of maximum wind speeds of typhoon
Chen Kongmo, Qin Zenghao
1990, (1): 69-79.
Abstract:
At present, it is still difficult to obtain an accurate maximum wind speed of typhoon with modern means,such as satellite survey, radar tracing and airplane reconnaissance.The performance of statistical equation established with observational maximum wind speed and the central pressure of typhoon is unstable,and it is unreliable in operational use.Therefore a general pressure field model of typhoon is introduced in this paper based on atmospheric motion equations and formulas are derived for computing the maximum wind speed around typhoon center over sea surface.The theoretical curves derived from these formulas are in good agreement with those using the statistic empirical curves of typhoon pressure-wind relations over the western Pacific.Tests were conducted for typhoons which occurred in 1973 and in 1983 and the strongest typhoons selected each year during 1970 and 1978,the results were satisfactory.Meanwhile the analyses of computing results showed that the effect of Coriolis force could be negligible and the eccentric-elliptical pressure structure of typhoon could be treated as circular symmetric.
Marine Chemistry
Preliminary study on the distribution of nutrients, organic matter, trace metals in sea surface microlayer in Xiamen Bay and Jiulong Estuary
Hong Huasheng, Lin Jie
1990, (1): 81-90.
Abstract:
The enrichment of nutrients (NO2-, NO3-, PO43-), suspended particles, organic matter (POC, PON,DOC), and trace metals (Cu, Ni, Cd) was determined in the sea surface microlayer of Xiamen Bay and Jiulong Estuary.The mean enrichment factors ([Xi]microlayer/[Xi]15cm in depth) mostly ranged between 1.0 and 2.0.The dissolved forms were the major forms of the components measured, the enrichment of dissolved organic matter and suspended particles could lead to the changes in the total amount and speciation of nutrients and trace metals.No correlation was observed between sample concentrations, speciation, enrichment factors and sample locations.However, some evidence shows that these parameters are correlated with sea state, indicating the complexity and dynamic nature of the sea surface microlayer.
Adsorption of uranyl complex ions on hydrous titanium oxide (HTO)——Ⅱ. Infrared spectrum investigation
Fu Wentong, Luo Bingkun
1990, (1): 91-96.
Abstract:
The i.r.spectra of Na4[UO2(CO3)3], Na[UO2(OH)3] and the surface species of uranium on HTO underthe condition of flowing natural seawater and concentrated seawater (NaCl-NaHCO3-U) were recorded, with the bands of uranyl of surface species obtained and the finding that iigands of surface species besides HTO are mainly water and OH, and there are some CO32- groups under the condition of natural seawater.Some relations between the complex properties and the j.r.spectroscopic characters for uranyl complexes were studied, and the transferred change quantity of surface complex was calculated.
Structure models for surface species of adsorption are herein presented and the mechanism for uranium adsorption is deduced.
The use of urushiol-titanium chela te polymer as an anticorrosive coating for marine application
Hu Binghuan, Chen Wending, Lin Jinhuo, Zhao Fang, Gan Jinghao
1990, (1): 97-107.
Abstract:
The present paper reports a new type of coating possessing with excellent anticorrosive properties for marine application.The coatings are urushiol-titanium chelate polymer.The present authors list the anticorrosive spectra of the new coating in various chemicals.The chemical structure of the new coating was studied using IR, GPC, DTA and TG techniques.The relationship between chemical structure and anticorrosive properties is also discussed.
The study of mixing rates and sedimentation rates in Meizhou Bay sediments
Chen Shaoyong, Li Wenquan, Shi Wenyuan, Huang Yipu
1990, (1): 109-117.
Abstract:
The applicability of the doubie-layer model for 210Pb chronology in coastal marine environments was discussed,which is successfully used in the study of mixing rates and sedimentation rates in Meizhou Bay.Differences among sedimentation rates deduced from 210Pb, 210Po, and 137Cs were compared.Mixing rates in the sediment surface layer were determined by means of excess 234Th.
Marine Geology and Geomorphology
Distribution of recent Ostracoda from the coastal zone of Gaode and Weizhou Island, Zhuang Autonomous Region of Guangxi
Ruan Peihua
1990, (1): 119-134.
Abstract:
This paper deals with the recent ostracods and their distribution in littoral zones.The ostracods studied in this paper are all from the coastal zones of Gaode and Weizhou Island, Zhuang Autonomous Region of Guangxi.The present study shows that the richness and diversity of the ostracods from Gaode area are rather lower as compared with those from Weizhou Island, where individual numbers increase constantly from supralittoral to sublittoral zones.The ostracod associations of Weizhou Island are similar to those reported from the east coast of the Weizhou Island, and most of them are littoral and benthic forms of the order Podocopida and only a few of them are members of the order Myodocopoda (e.g.Rutiderma, Cylindroleberis and Polycope).In this paper, the distributive character of the ostracods in the studied areas is analysed and discussed synthetically on the ground of their ecology, which will provide new information for the study of ecologic habitats, biogeographic provinciality and the Cenozoic biostratigraphy of ostracods.
Marine Biology and Fishery
Research on the short-term fishery forecasting of Spanish mackerel (Scomberomerus niphonius)
Wei Sheng, Zhou Binbin
1990, (1): 135-144.
Abstract:
This paper presents the use of the hydrographic factors in short-term fishery forecasting of the spawning migration stock of the Spanish mackerel and salinity describes more concretely the correlativity of water temperature, salinity and air temperature with the fishing season in spring.The data have been collected from the hydrographic environmental investigation at the fixed position on the sea and the telegraph recordings of the drift net operation in the spring fishing season during the period of April and May from 1972 to 1980.The correlation coefficients of various factors with the data of the fishing season have been calculated by using the monadic regression method.
The main reference targets of the forecasting are:(1) By using the upper-layer water temperature as the forecasting factor at the beginning of the fishing season, the accuracy is high; (2) the distribution and location of the isotherm of the upper-layer water at 10℃ at the beginning of April are used as an important factor for determining the location and the range of the central fishing area of the Spanish mackerel; (3) whether a low temperature area at 8℃ existing at the Estuary of the Changjiang River can be used as an important factor for forecasting the migration distribution of the Spanish mackerel moving to the north.
Effects of a mixture of Cu, Cd, Hg and Zn on marine plankton: Marine Ecosystem Enclosure Experiment
Wu Jinping
1990, (1): 145-150.
Abstract:
Five experiment ecosystems (MEEE) were employed in April, 1985 to test the effects of a mixture of Cu, Cd, Hg, Pb and Zn on a subtropical planktonic ecosystem in Xiamen Bay, Xiamen, China.The results indicated that the ppb-level of the mixture could suppress the planktonic production.Zooplankton in Xiamen were very sensitive to the metal contamination, especially the larvaceans.
The effects of sediment from an industrial outfall area on a marine planktonic ecosystem
Wu Jinping
1990, (1): 151-158.
Abstract:
Sediment from Xiamen industrial area was added to marine ecosystem enclosures to test the effects on the planktonic communities in Xiamen Bay, China, in April, 1985.Sediments were added at two concentrations, 11.2 and 112 ppm dry wt.respectively.The species of phytoplankton did not change as compared with the control, but the number of diatoms markedly decreased in the sediment treated enclosures.A suppression of photosynthesis was presumed to be due to light attenuation by the added sediment.Microflagellates, zooplankton and bacteria were resistant to sediment increase in water column.