共查询到18条相似文献,搜索用时 125 毫秒
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海洋内波是海洋中常见的现象,与表面波一样是海洋中的一种重要动力形式,其表面流场的辐散辐聚会引起海表温度的微弱变化,文章通过冷表皮剪切模型阐述了海洋内波表面流场调制海表温度的具体物理机制,并对现有冷表皮剪切模型进行改进,使其仿真结果与海上实验所得海表温度波动量级一致。最终通过海上实验验证,结果表明改进的冷表皮剪切模型是可信的。 相似文献
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为了研究海洋内波,设计了一种海洋内波现场测量系统.该系统利用水下络车拖动测量平台在水中上下往复运动,在运动过程中测量平台携带的各种测量仪器连续采集与海洋内波有关的各种海洋参数(温度、盐度、深度和海流),并定期通过卫星传输到岸站.该系统可有效地测量各种海洋参数,通过卫星传输测量数据的方法极大地提高了数据的时效性. 相似文献
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海洋内波是发生在海水内部的一种波动现象,而垂向结构的求解是研究海洋内波的基础.首先,给出了应用Thompson-Haskell算法求解海洋内波垂向结构的主要过程,即海洋内波的色散关系以及垂向速度幅值沿水深分布的计算公式.其次,给出了数值求解海洋内波水平波数以及垂向速度幅值沿水深分布的流程图.然后,基于修正的Holmboe模式密度分布,计算了海洋内波的水平波数、色散关系以及垂向速度幅值沿水深的分布.数值计算表明,TH方法以及提出的色散关系和垂向速度幅值沿水深分布的求解方案,可以给出较好的数值结果. 相似文献
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水下绞车及其在海洋内波现场测量系统的应用 总被引:1,自引:1,他引:0
为了实现海洋内波自动测量,设计了一种水下绞车.海洋内波现场测量系统利用水下绞车的收索和放索控制测量平台在海水中上下往复运动,在此过程中测量各种海洋参数.文中主要讲述了水下绞车的驱动电路、保护电路以及海洋内波现场测量系统的工作流程.实践结果表明,水下绞车实现了无人值守工作,在海洋测量方面具有较强的使用前景. 相似文献
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潜艇尾迹内波的实验研究 总被引:2,自引:0,他引:2
由于潜艇噪声越来越小,非声探潜技术显得越来越重要.实际海洋中存在温度和盐度梯度,水下航行的潜艇产生的扰动和尾流的坍塌会在海洋中产生内波.由于内波存在时间较长,频率范围大,其特征难以消除,所以内波容易被检测到.本文利用直流电导率检测技术,实验研究了潜艇尾迹内波产生的特点和规律,得出了潜艇尾迹内波与分层流梯度的关系和尾迹内波随时间和空间的衰减规律.在线性分层中内波信号在Nt大约为40时还可以检测到.潜艇尾迹内波在空间上可检测到的区域接近椭圆形.实验研究表明利用直流电导率法检测水下潜艇的尾流和内波是可行的. 相似文献
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J.M. de Kok 《Journal of Marine Systems》1997,12(1-4)
A three-dimensional finite difference tidal model, including advective and diffusive transport of salinity, is used in the two-layer model for simulation of Rhine water outflow. Layer depths are adjusted in a way that no advective transports between upper and lower layer take place in case of sufficiently stable stratification.Model results show frontal eddy development related to (limited) growing internal waves in case of weak northeasterly to southeasterly winds. It is shown that baroclinically unstable conditions occur, related to vertical velocity shear, resulting in frontal meanders with wave lengths between 18 and 30 km. Satellite images of sea surface temperature show a comparable behaviour of the temperature front, which is strongly correlated with the salinity front of the Rhine plume. 相似文献
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照片尺寸为20mm*30mm;最好不用红色背景建立海面光学成像理论模型研究海洋内波是国内外有关研究机构的热点之一。文章初步讨论了太阳耀斑在光学卫星上的影响,结合海面光学可见光反射率模型,基于Cox-Munk模型计算了海面的辐亮度,并研究了海面风速、海面油膜对海面太阳辐亮度影响,并分析比较了它们的计算结果。 相似文献
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潜航体在海水界面兴起的内波夹角 总被引:1,自引:1,他引:0
水下潜航体在分层海水中兴起内波,这与水面船在海面兴起的Kelvin波并不一样。其中一个具体的区别是两类波迹的夹角大小。对Kelvin波的研究已相当成熟,对内波的研究正方兴未艾。本文是有关内波系列研究工作的一部分,采用一种简单而直截了当的计算方法,分近、远场具体计算出水下潜航体在海中兴起的内波夹角大小和范围。 相似文献
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《船舶与海洋工程学报》2015,(4)
The main goal of this paper is to investigate sound scattering from the sea surface, by Kuo's small perturbation method(SPM), in the Persian Gulf's environmental conditions. Accordingly, the SPM method is reviewed, then it is demonstrated how it can accurately model sound scattering from the sea surface. Since in Kuo's approach, the effects of surface roughness and sub-surface bubble plumes on incident sounds can be studied separately, it is possible to investigate the importance of each mechanism in various scattering regimes. To conduct this study, wind and wave information reported by Arzanah station as well as some numerical atmospheric models for the Persian Gulf are presented and applied to examine sound scattering from the sea surface in the Persian Gulf region. Plots of scattering strength by Kuo's SPM method versus grazing angle for various frequencies, wave heights, and wind speeds are presented. The calculated scattering strength by the SPM method for various frequencies and wind speeds are compared against the results of critical sea tests 7(CST-7). The favorable agreement achieved for sound scattering in the Persian Gulf region is indicative of the fact that the SPM method can quite accurately model and predict sound scattering from the sea surface. 相似文献
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《船舶与海洋工程学报》2017,(3)
Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers are assumed to be fixed at a certain distance in front of a vertical rigid wall. Using linear water wave theory and Darcy's law for flow past porous structure, the physical problem is converted into a boundary value problem. Using eigenfunction expansion in the uniform bottom bed region and modified mild-slope equation in the varying bottom bed region, the mathematical problem is handled for solution. Moreover, certain jump conditions are used to account for mass conservation at slope discontinuities in the bottom bed profile. To understand the effect of dual porous barriers in creating tranquility zone and minimum load on the sea wall, reflection coefficient, wave forces acting on the barrier and the wall, and surface wave elevation are computed and analyzed for different values of depth ratio, porous-effect parameter, incident wave angle, gap between the barriers and wall and slope length of undulated bottom. The study reveals that with moderate porosity and suitable gap between barriers and sea wall, using dual barriers an effective wave trapping system can be developed which will exert less wave force on the barriers and the rigid wall. The proposed wave trapping system is likely to be of immense help for protecting various facilities/infrastructures in coastal environment. 相似文献
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Application of new parameterizations of gas transfer velocity and their impact on regional and global marine CO2 budgets 总被引:1,自引:0,他引:1
One of the dominant sources of uncertainty in the calculation of air–sea flux of carbon dioxide on a global scale originates from the various parameterizations of the gas transfer velocity, k, that are in use. Whilst it is undisputed that most of these parameterizations have shortcomings and neglect processes which influence air–sea gas exchange and do not scale with wind speed alone, there is no general agreement about their relative accuracy.The most widely used parameterizations are based on non-linear functions of wind speed and, to a lesser extent, on sea surface temperature and salinity. Processes such as surface film damping and whitecapping are known to have an effect on air–sea exchange. More recently published parameterizations use friction velocity, sea surface roughness, and significant wave height. These new parameters can account to some extent for processes such as film damping and whitecapping and could potentially explain the spread of wind-speed based transfer velocities published in the literature.We combine some of the principles of two recently published k parameterizations [Glover, D.M., Frew, N.M., McCue, S.J. and Bock, E.J., 2002. A multiyear time series of global gas transfer velocity from the TOPEX dual frequency, normalized radar backscatter algorithm. In: Donelan, M.A., Drennan, W.M., Saltzman, E.S., and Wanninkhof, R. (Eds.), Gas Transfer at Water Surfaces, Geophys. Monograph 127. AGU,Washington, DC, 325–331; Woolf, D.K., 2005. Parameterization of gas transfer velocities and sea-state dependent wave breaking. Tellus, 57B: 87–94] to calculate k as the sum of a linear function of total mean square slope of the sea surface and a wave breaking parameter. This separates contributions from direct and bubble-mediated gas transfer as suggested by Woolf [Woolf, D.K., 2005. Parameterization of gas transfer velocities and sea-state dependent wave breaking. Tellus, 57B: 87–94] and allows us to quantify contributions from these two processes independently.We then apply our parameterization to a monthly TOPEX altimeter gridded 1.5° × 1.5° data set and compare our results to transfer velocities calculated using the popular wind-based k parameterizations by Wanninkhof [Wanninkhof, R., 1992. Relationship between wind speed and gas exchange over the ocean. J. Geophys. Res., 97: 7373–7382.] and Wanninkhof and McGillis [Wanninkhof, R. and McGillis, W., 1999. A cubic relationship between air−sea CO2 exchange and wind speed. Geophys. Res. Lett., 26(13): 1889–1892]. We show that despite good agreement of the globally averaged transfer velocities, global and regional fluxes differ by up to 100%. These discrepancies are a result of different spatio-temporal distributions of the processes involved in the parameterizations of k, indicating the importance of wave field parameters and a need for further validation. 相似文献