机载雷达高度计对海况及海面风速的测量研究     

潘家祎  袁业立  姜景山  郑全安 《海洋与湖沼》1996,27(6):598-604

运用我国自行研制的ＺＨＧ－１型Ｘ波段机载雷达高度计于１９９５年４月１３日－４月１８日在青岛附近海域进行的海上飞行实验数据，及导出的均方根波高、有效波高、均方根波陡算法模型，得到了上述海况参数值。  相似文献   

黄海的风、潮混合特征及其对冷水团边界的影响     

赵保仁  曹德明  潘海  涂登志 《海洋科学集刊》1994,(35):1-10

本文第一作者早在1985年就提出,潮混合效应控制着夏季黄海冷水团的边界及海面冷水分布(赵保仁,1985)。1987年又进一步通过水文调査资料和卫星图片给出了黄海周围的浅水陆架锋(或称潮汐锋)的分布及强锋区的跨锋断面中的温度、盐度和坏流结构特征,并指出夏季的黄海沿岸流在性质上属沿锋面运动的强流(赵保仁,1987a,b),而后又对黄海西部的陆架锋进行了一次专门调査(赵保仁等,1991)。此外,他还指出黄海的强温跃层的形成和转移现象也与潮混合现象密切相关(赵保仁,1989)。因此,研究潮混合现象对阐明发生在黄海的多水文物理现象都是至关重要的。 为深入了解黄海的潮混合特征,作者把渤海、黄海和东海作为一个整体完成了一次精度较高的潮汐、溯流数值计算,在潮汐、潮流的分布方面,揭示了前人尚未阐明的一些特征。本文根据这些数值结果,计算了近最大潮流流速和层化参数,阐明了渤海、黄海和东海的潮混合特征及其对降温期黄海冷水团分布变化的影响。此外,还用 Sim pson等人(1981)的能量模式计算了南黄海西部的风、潮混合效率。  相似文献   

Robust adaptive control of underactuated ships on a linear course with comfort     

K. D. Do  J. Pan  Z. P. Jiang   《Ocean Engineering》2003,30(17):2201-2225

This paper addresses an important problem in ship control application—the robust stabilization of underactuated ships on a linear course with comfort. Specifically, we develop a multivariable controller to stabilize ocean surface ships without a sway actuator on a linear course and to reduce roll and pitch simultaneously. The controller adapts to unknown parameters of the ship and constant environmental disturbances induced by wave, ocean current and wind. It is also robust to time-varying environmental disturbances, time-varying change in ship parameters and other motions of the ship such as surge and heave. The roll and pitch can be made arbitrarily small while the heading angle and sway are kept to be in reasonably small bounds. The controller development is based on Lyapunov’s direct method and backstepping technique. A Lipschitz continuous projection algorithm is used to update the estimate of the unknown parameters to avoid the parameters’ drift due to time-varying environmental disturbances. Simulations on a full-scale catamaran illustrate the effectiveness of our proposed controller.  相似文献   

分潮波模型多资料数值计算方法研究　Ⅱ.有限差分最小二乘方法     

潘文波  孙文心  王骥 《中国海洋大学学报(自然科学版)》1996,(2)

对含多资料的分潮波模型的超定问题进行探讨，建立一种有限差分—最小二乘方法，该方法使得岸边资料直接进入了计算方程，并保证岸界法向流速为零条件。通过对渤海的四大分潮的试算，证实本方法可行。  相似文献   

Optimal Design for Main Dimensions of a 75000t Floating Production and Storage Vessel     

Tan Jiahua  Ma Wei  Pan Bin Associate Professor  Shanghai Jiao Tong University  Shanghai Lecturer  shanghai Jiao Tong University  Shanghai 《中国海洋工程》1992,(1)

The basis, process and results of the demonstration of the main dimensions of a 75000t floating production and storage vessel are discussed in this paper. A simple but reliable orthogonal design method is applied in the main dimension optimization. The ideas of gradual approximation and feedback from various aspects are put into effect. During the demonstration, in order to make the model tally with the actual situation, the draft design is closely related to the computational analysis, so that the demonstration model can be verified at any time; the handling of the overall system is closely related to the research of each item, which is beneficial not only to the mastery of various regularities, but also to the balance of decisions. Finally, according to the computational results and the regularities obtained from analysis, the main dimensions are determined.  相似文献   

Relationship between the depth of visibility of Secchi disk and biooptical characteristics of the Black-Sea waters     

V. I. Man’kovsky 《Physical Oceanography》2001,11(5):491-494

We present the parameters of empirical relationships between the depth of visibility of Secchi disk and optical and biological characteristics of the Black-Sea surface waters. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

Geological structure of the Curonian Spit (of the Baltic Sea) and its evolution history (revised)     

E. N. Badyukova  L. A. Zhindarev  S. A. Luk’yanova  G. D. Solov’eva 《Oceanology》2007,47(4):554-563

The origin and evolution history of the Curonian Spit in the Baltic Sea are discussed based on geological and geomorphologic data. Evidence of the correlation between the spit formation stages and the Holocene sea level oscillations is presented. The ledges of moraine basement and marine accumulative features formed a single barrier. Its subsequent transformation occurred under the influence of the wave-related lithodynamic and eolian processes.  相似文献   

Estimating the underwater light field from remote sensing of ocean color     

Cheng-Chien Liu  Richard L. Miller  Kendall L. Carder  Zhongping Lee  Eurico J. D’Sa  James E. Ivey 《Journal of Oceanography》2006,62(3):235-248

We present a new approach that incorporates two models to estimate the underwater light field from remote sensing of ocean color. The first employs a series of analytical, semi-analytical, and empirical algorithms to retrieve the spectrum of inherent optical properties (IOPs), including the absorption and the backscatter coefficients, from the spectrum of remote sensing reflectance. The second model computes the profile of photosynthetically available radiation E _0,PAR (z) for a vertically homogeneous water column using the information of the retrieved IOPs and the ambient optical environment. This computation is based on an improved look-up table technology that possesses high accuracy, comparable with the full solution of the radiative transfer equation, and meets the computational requirement of remote sensing application. This new approach was validated by in situ measurements and an extensive model-to-model comparison with a wide range of IOPs. We successfully mapped the compensation depth by applying this new approach to process the SeaWiFS imagery. This research suggests that E _0,PAR (z) can be obtained routinely from ocean-color data and may have significant implications for the estimation of global heat and carbon budget.  相似文献   

Diagnosis of the interaction of tropical cyclones     

M. I. Yaroshevich  L. Kh. Ingel’ 《Izvestiya Atmospheric and Oceanic Physics》2006,42(6):704-708

At present the mutual influence of tropical cyclones (TCs) has been investigated to a much lesser extent than the cyclones themselves. Most frequently, such investigations are restricted to the study of the influence of the interaction of two TCs on their motion. However, actually, the mutual influence of TCs is much more diverse. For example, each cyclone alters the state of the medium (in particular, decreases the heat store of the upper ocean layer), i.e., affects the subsequent cyclones. Under conditions of a limited energy resource of the medium, cyclones, existing simultaneously, “compete,” to a degree, with each other. These and other similar circumstances have made it practical to consider tropical cyclones and the environment as interdependent elements of a complex open system. This study considers two versions of nonlinear models describing the interaction of TCs with the upper ocean layer and with one another similarly to a number of well-known and verified models of synergetics (interaction of populations, dynamics of optical quantum generators). It is shown that the models reproduce some very important qualitative features of the evolution of TC intensity.  相似文献   

Average grain-size parameters of unlithified sediments in the World Ocean     

V. N. Sval’nov  T. N. Alekseeva 《Oceanology》2006,46(4):545-556

The high diversity of grain-size parameters of marine and oceanic sediments is determined by hydrodynamical and gravitational processes. Grain-size spectra of the sediments in the World Ocean are represented by two main types. Filtering organisms that passively inherit the proportions of clayey fractions in suspended matter only accelerate the deposition of fine particles, not influencing their distribution at the bottom.  相似文献