Distribution and abundance of Pseudeuphausia sinica off the Changjiang River Estuary (30°00'-32°00'N, 122°00'-123°30'E), the East China Sea were studied in relation to environmental features associated with the regional warming. P. sinica is a subtropical species. Off the Changjiang River Estuary, its abundance reached maximum in summer. To examine spatial and temporal changes of P. sinica off the Changjiang River Estuary, the authors have combined all available sampling data in 1979, 1981, and 2000-2007. This database shows that a significant increase in abundances of P. sinica was observed in spring of 2000-2007 as compared with 1979, 1981. The abundance of P. sinica increased from 0.18-0.21 ind./m3 in 1979 and 1981 to 0.68-4.00 ind./m3 in 2000-2007. Accordingly, the sea temperature increased obviously from spring of 1979, 1981 to the 2000s. The authors further found a positive relationship between average surface temperature and average abundance of P. sinica. Regional warming, together with the release of predator induced stress due to a sharp decline in the abundance of its predator (e.g., fishes), were thought to be responsible for the increase in abundance of P. sinica in water off the Changjiang River Estuary.
New data on Anthomedusae are included.Seven new species and 2 new combinations are described.An additional Teissiera polypofera Xu,Huang and Chen,1991 is redescribed and its position of taxonomy is discussed.Other lists of species on Anthomedusae are summarized.
In this paper, the tree cluster analysis and ISODATA of fuzzy cluster are made on the basis of the results (Chen et al,1993) obtained by using the principal component analysis based on the hydroclimatic values over the years of the China seas,where the climatic field may be divided into three climatic zones, 9 hydroclimatic regions and 1 climatic subregion. Comparison of the distribution characteristics of hydrologic seasons with those of marine fauna and flora indicafes that each climatic region possesses its inherent seasonal characteristics and biota distribution, and corresponds with each other. This fact proves that the division of the above-mentioned 10 climatic regions is reliable.
With the launch of altimeter, much effort has been made to develop algorithms on the wind speed and the wave period. By using a large data set of collocated altimeter and buoy measurements, the typical wind speed and wave period algorithms are validated. Based on theoretical argument and the concept of wave age, a semi-empirical algorithm for the wave period is also proposed, which has the wave-period dimension, and explicitly demonstrates the relationships between the wave period and the other variables. It is found that Ku and C band data should be applied simultaneously in order to improve either wind speed or wave period algorithms. The dual-band algorithms proposed by Chen et al. (2002) for the wind speed and Quilfen et al. (2004) for the wave period perform best in terms of a root mean square error in the practical applications.
With the launch of altimeter,much effort has been made to develop algorithms on the wind speed and the wave period.By using a large data set of collocated altimeter and buoy measurements,the typical wind speed and wave period algorithms are validated.Based on theoretical argument and the concept of wave age,a semi-empirical algorithm for the wave period is also proposed,which has the wave-period dimension,and explicitly demonstrates the relationships between the wave period and the other variables.It is found that Ku and C band data should be applied simultaneously in order to improve either wind speed or wave period algorithms.The dual-band algorithms proposed by Chen et al.(2002) for the wind speed and Quilfen et al.(2004) for the wave period perform best in terms of a root mean square error in the practical applications.
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.
A series of numerical simulations about a small scale (aspect ratio:63.2) flexible pipe undergoing forced harmonious oscillation and vortex-induced vibration (VIV) have been taken into account. The wake hydrodynamics and pipe deformation were accomplished by ANSYS MFX solution strategy designed for fluid-structure interaction (FSI) problem with well-performed LES model. The configuration of structured mesh, multi-domain design, different mesh stiffness admeasured by User Fortran ensured that the numerical task was competent to deal with large deformation related to this case. The introduction of instantaneous amplitude definition and modeless component decomposition method (Chen and Kim, 2008) was helpful to reveal much more information from modal analysis. Most results from numerical simulation are generally consistent with those from model test (Choi and Hong, 2000) via the comparison between them. As supplementary to model test, visualization of the vortex wake was also provided. It has been proved that the forced oscillation doesn't only excite a complicated dumbbell-like wake pattern around the outer thimble, but also results in inner flow inside the PVC pipe. The velocity of the inner flow increases with the frequency of forced oscillation.
利用活体观察和蛋白银染色技术对采自中国南海近岸的六种旋唇类纤毛虫：伍氏游仆虫Euplotes woodruffi Gaw，1939、缩颈半腹柱虫Hemigastrostyla enigmatica（Dragesco and Dragesco-Kernéis，1986） Song and Wilbert，1997、黄色新尾柱虫Neourostylopsis flavicana（Wang et al.，2011） Chen et al.，2013、美丽原腹柱虫Protogastrostyla pulchra（Perejaslawzewa，1886） Gong et al.，2007、膜泡伪小双虫Pseudoamphisiella alveolata（Kahl，1932） Song and Warren，2000和海洋伪卡尔虫Pseudokahliella marina（Foissner et al.，1982） Berger et al.，1985等进行活体形态特征和纤毛图式的研究。其中，美丽原腹柱虫、膜泡伪小双虫和海洋伪卡尔虫均为中国南海的新纪录，形态特征上与中国其他种群存在不同程度的差别。此外，对来自红树林生境的伍氏游仆虫和缩颈半腹柱虫，以及来自养殖水体的黄色新尾柱虫进行了详细的形态特征描述。
A wave forecasting system using FUNWAVE-TVD which is based on the fully nonlinear Boussinesq equations by Chen (2006) was developed to provide an accurate wave prediction in the Port of Busan, South Korea. This system is linked to the Korea Operational Oceanographic System (KOOS) developed by Park et al. (2015). The computational domain covers a region of 9.6 km×7.0 km with a grid size of 2 m in both directions, which is sufficient to resolve short waves and dominant sea states. The total number of grid points exceeds 16 millions, making the model computational expensive. To provide real-time forecasting, an interpolation method, which is based on pre-calculated results of FUNWAVE-TVD and SWAN forecasting results at the FUNWAVE-TVD offshore boundary, was used. A total of 45 cases were pre-calculated, which took 71 days on 924 computational cores of a Linux cluster system. Wind wave generation and propagation from the deep water were computed using the SWAN in KOOS. SWAN results provided a boundary condition for the FUNWAVE-TVD forecasting system. To verify the model, wave observations were conducted at three locations inside the port in a time period of more than 7 months. A model/model comparison between FUNWAVE-TVD and SWAN was also carried out. It is found that, FUNWAVE-TVD improves the forecasting results significantly compared to SWAN which underestimates wave heights in sheltered areas due to incorrect physical mechanism of wave diffraction, as well as large wave heights caused by wave reflections inside the port.