1995 Vol. 14, No. 2

Display Method:
A proposed directional function and wind-wave directional spectrum
Wen Shengchang, Wu Kejian, Guan Changlong, Sun Shicai, Zhang Dacuo
1995, (2): 155-166.
A directional function for frequencies equal to and larger than the peak frequency of a wind-wave frequency spectrum is constructed by fitting the angular spreading based on the analytically derived directional spectrum of Wen et al. (1993, Journal of Oceanography, 49 (2), 131-147, 149-172).For frequencies smaller than the peak frequency, the directional function is obtained by comparing and analyzing existing formulas.The nondimensional wind-wave frequency spectrum of Wen et al. (1994, Progress in Natural Seience, 4 (4), 407-427;4 (5), 586-596) has been used together with the directional function just mentioned to obtain the directional spectrum for easier application.
A method to predict typhoon waves
Yang Chuncheng, Dai Mingrui, Gao Zhihua, Cheng Zhan, Xu Fuxiang, Liu Yu, Li Fengjin, Li Jie, Su Dongfu, Zhang Dacuo, Xu Qichun
1995, (2): 167-180.
The presented method for numerical typhoon wave prediction is composed of a scheme for real time pressure forecasts, a marine wind numerical model and a typhoon wave numerical model.In the Northwest Pacific Ocean and China seas where water depth is over 20 m, a hybrid wave model[Wen Shengchang, Zhang Dacuo, Chen Bohai and Guo Peifang.1989, Acta Oceannlogica Sinica, 8 (1), 1-14; Zhang Dacuo, Wu Zengmao, Jiang Decai, Rang Wei, Chen Bohai, Tai R'eitao, R'en Shengchang, Xu Qichun and Guo Peifang.1992, Acta Oceanologica Sinica, 11 (2), 157-178] is employed with 10°×10° grids, while in the South China Sea and East China Sea where typhoon frequently appears, the WAM model (WAMDI Group.1988, Journal of Physical Oceanography, 18, 1755-1810) of shallow water version is embedded with (1/4)°× (1/4)° grids.The boundary condition at the open boundary of the WAM model is provided by the hybrid model.After 3 a of testing forecasts (Yang Chuncheng, Dai Mingrui and Zhang Dacuo.1992, International Symposium on Tropical Cyclone Dusaaters, October 12-16, Beijing, 404-409)and improvement, this system was put into operational use on the forecasting computer network of National Marine Environment Forecast Center of China in June, 1993.The wave predictions of 22 typhoon events show that the system is stable and prompt, and the forecast results are satisfactory.This system provides reliable numerical products for the disaster-prevention forecasts.The product is broadcasted in CCTV News at every noon.
Research on the spectral analysis and test method of period signals in monthly mean sea level
Ma Jirui, Tian Suzhen, Zheng Wenzhen, Chai Xinmin
1995, (2): 181-190.
This paper summarizes the general methods, existing problems and their causes of the period analysis for the monthly mean sea level and points out that it is the key to the analysing period signals and forecasting the change trend of the monthly mean sea level that the periods of the signals are selected reasonably.As there are often many period signals in these series, nonlinear effects exist between pairs of period signals.In order to avoid the false periods that may be introduced due to the effects of side lobes and the periods with statistical phase significance coherence that may be introduced due to the effects of nonlinear effects and their restraint to other period signals, the maximum entropy spectral analysis and the corresponding significance period test may be performed repeatedly on the basis of the bispectrum analysis and meanwhile the most significant period component is filtered out by the least square filtering method, i.e., the method of the significance period analysis with mixed spectra modeled by a nonlinear system is adopted and the signal periods approaching the reality are selected one by one.The examples of the bispectrum analysis, the signal period analysis by mixed spectra and the fitting parameters for combined period components with linear trend in the time series of monthly mean sea level are given in this paper.
Period components in the monthly mean sea level variations in the Pacific Ocean
Tian Suzhen, Ma Jirui, Zheng Wenzhen, Chai Xinmin, Zhang Qin
1995, (2): 191-200.
To study the period components in the monthly mean sea level variations in the Pacific Ocean, this paper analyses the monthly mean series of 236 tide gauge stations in the Pacific on the basin of the improved analytical method of the monthly mean sea level period signals. The results show that the oscillation periods of the sea level series are not fixed, but vary with stations. This paper also dmcusses the existences oI the quart-2 years atmospheric oscillation period, the 3-7 a period related to the El Nino events, sunspots, double sunspots and the 25-30 a overlength oscillation periods.
Observation of clouds and solar radiation over the Pacific Ocean as relation to global climate
Farn Parungo, Clarence Nagamoto, Cecilia M. I. R. Girz, Jeff Torgerson, Zhou Mingyu
1995, (2): 201-207.
During a research cruise over the Pacific Ocean in 1989, solar irradiance was measured with a broad-band pyranometer along the cruise track.Cloud cover was photographed with an all-sky time-lapse camera.Cloud types were observed and recorded.The data show that both the types and the amounts of clouds affeet radiation fluxes on the sea surface.For low-level and middle-level clouds, the correlations (r) between measured irradiance (in percent of calculated maximum irradiance) and cloud amount (in fraction of sky) were significant:r=-0.79 and -0.66, respectively.For high-level clouds, the correlation was not significant;r=-0.21.The results indicate that cloud shortwave forcing is a major modifier of the earth's surface insulation and change of cloud amount may affect global climate.
The concentration of total dissolved CO2 in surface water in ENSO event——The results of investigation during TOGA expeditions
Ma Liming, Zhang Bin, Qiao Ran
1995, (2): 209-223.
The observations of total dissolved CO2 (TCO2) in surface water on the range from 115°E to 165°E, from 10°S to 20°N from Dec.1986 to Jun.1990, present following results:There was distinguished difference of distribution of TCO2 between during El Nino and La Nina, especially on east of 155°E and equator.During El Nino TCO2 was the lowest (TCO2, 1 900 pmol/kg) in seven cruises and proportional to salinity, the dominant effect of current was from North Equatorial Current (NEC).During La Nina the value of TCO2 became the highest (CO2 >1 900 μmol/kg) in range of Equatorial Upwelling, the dominant effect was from South Equatorial Current.The effect of air-sea exchange and biological activity increased.
Relationship between biogeochemical features of biogenic elements and flocculation in the Changjiang Estuary
Lin Yi'an, Tang Renyou, Li Yan, Dong Henglin, Guan Xuwei, Chen Yinzu
1995, (2): 225-234.
This paper reports the relationship between the biogeochemical characteristics of C.N.P and flocculation and settling of suspended materials in the Changjiang Estuary.Regional activities of bacteria and the plankton and biogeochemical processes at the water-particle interface under some environmental conditions are quite variable.This leads to the transition of material phase with speciation variation of elements C.N.P.in the transfer processes.Therefore, the composition and reactivity of particle surface and dissolved constituent are modified, affecting the stability of the particulate dispersion system.In summer, the concentration of NO3- and PO43- are positively correlated with turbidity, while the weight percentage of PON, POC and PP are negatively correlated with turbidity.When particles in the river move seaward, two zones can be distinguished:ⅰ) zone with maximum flocculation speed, in salinity 0.1-2.0;ⅱ)zone with huge coagulating particles netting and high turbidity at the bottom, in salinity 2-11.The highest values of C/N in particles (or the low valley of C.E.C.of particle surface) appear in the two zones.These results demonstrate that the biogeochemical action is one of the major factors and mechanisms to dominate the flocculation of particles in the Changjiang Estuary.
A study on benthic community structure in west of the Taiwan Strait and near the Taiwan Shoals
Wu Qiquan, Jiang Jinxiang, Xu Huizhou, Cai Erxi, Lin Shuangdan
1995, (2): 235-245.
Community structures on benthic organisms in the Taiwan Strait based on 4 surveys during 1984-1985 are studied.Seven communities can be divided according to cluster analysis and community structure indexes.The distribution.structural feature of different communities.relation between environmental factors and community are also dixussed.The benthic organism community takes the.Asymmetron cultellum as the representative at the vast and deep east area in the south of the Taiwan Strait.The results provide new data for resource explmoation and biology study.
Bacterial kinetics and environmental capacity in he Western Xiamen Harbour
Ye Dezan, Ni Chunzhi, Zhou Zongcheng, Yao Ruimei, Zeng Huoshui, Lin Yanshun, Liang Ziyuan, Gu Jingyu
1995, (2): 247-259.
A principle, which has usually been applied to biochemical treatment for waste water is presently introduced into the study on marine microbiological ecology and employed in the estimation of environmental capacity.By means of a selection of 3 models for the microbial growth or for its oxygen consumption and determinations of concerned parameters in the field and the laboratory, the environmental capacity for the Restern Xiamen Harbour is evaluated to be 37 t·d-1 of BOD5 in gross or 28 t·d-1 in net (with some 2500 of the gross capacity consumed by a present ecosystem) if BOD5 is controlled without excess of 3 mg·dm-3 in the sea water; it means that an amount of domestic waste water equal to 28 t of BOns can be naturally self-purified in this sea area everyday.Furthermore it is found that the K value, a constant of oxygen-consumed kinetics, shows possitive correlation to the concentration of BOD5 in the same system and total bacterial number (TB) in the seawater also to BOD5 with a regression equation TB (108 dm-3)=9.91×BOD5 (mg·dm-3)+1.74 (n=32.r=0.544 1, p<0.01).
Studies on marine nanodiatoms in Fujian coastal waters of China in winter
Liu Shicheng, Gao Yahui, Cheng Zhaodi
1995, (2): 261-268.
For the first time, nanodiatoms (<20pm) and microdiatoms (>20pm) in the coastal waters of Xiamen, Shandu, Fuqing, Haitan, Putian and Meizhou of Fujian Province along the western coast of the Taiwan Strait are quantitatively counted by TEM in the paper.The results show that the number of nanodiatoms from all the station is more than that of microdiatoms, accounting for 92% of the species collected.This indicates that nanodiatoms constitute a large microcosm of the whole diatom group.Unfortunately, the lower resolution of light microscopes which have been used in the study of diatoms in the past makes this unneglectable microcosm unnoticed.Thanks to TEM, 47 species of nanodiatoms are identified and four of them are for the first time recorded in China.The new records are Hantzschia spectabilis, Navicula crucigera, Nav.spicula and Nitzs.rosenstockii.
The effects of immobilization on physiology and ultrastructure of unicellular alga Platymonas subcordiformis
Zhang Xuecheng, Wu Xiaonan, Li Yonghong
1995, (2): 269-275.
In the present paper, the unicellular green alga Platymonas subcordiformis was entrapped in 2% (W/V) alginate, treated with CaCl2 at different concentrations (0.5, 0.75, 1.0, 1.5 and 2.0 mol/dm3), cultured at 15℃ and 25℃.The growth rate and morphology were studied and photosynthesis and respiration rates were measured.The optimum conditions of immobilized culture is in 0.5 mol/dm3 of CaCl2, at 25℃.Photosynthesis rate of immobilized cells is higher than free cultivated cells, and that at 15℃ than at 25℃.Under scanning electropic microscope, it was shown that the immobilized cells had larger size and rougher surface.The relationship between growth of immobilized cells and abiotic factors and the prospects of applying immobilized cultivation are also discussed.
Biochemical evidence for genetic relationship between the bisexual and parthenogenetic Artemia in China
Gao Mingjun, Cai Yaneng, Ge Lan
1995, (2): 276-281.
Cytological studies on neurosecretory cell of the X-organ in Scylla serrata
Shangguan Bumin, Li Shaojing
1995, (2): 283-290.
Studies on influence of diet on dry weight and chemical element(C, H, N) content of larval Scylla serrata
Wang Guizhong, Zeng Chaoshu, Li Shaojing, Lin Qiongwu
1995, (2): 291-300.
Application of purple nonsulphur bacterium Rhodopseudomonas sp.in spat rearing of Bay Scallop Argopecten irradians irradians
Ding Meili, Li Guangyou, Zhang Xiamei
1995, (2): 301-303.