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101.
102.
本文给出了一种从SASS测量的后向散射强度手数据中反演出大尺度海洋风场的新方法。计算结果与Peteherych等利用SASS表面风分析的结果比较在风向上是吻合的,在风速上本文所得结果更宇海面赵实风速。上述结果说明本文所采用的多解排除对两波束散射计探测海面风场的反演是成功的。 相似文献
103.
针对常垂直湍流系数和变垂直湍流系数两种情况,给出了开阔静止海面对风应力的非定常响应的解析表达式,并讨论了水深,风应力强弱对响应过程的影响,尽管没有考虑风场的非定常性,但本文的结果对理解海洋对风应力的非定常响应过程具有一定的帮助,对分析海面停风后的消衰过程也具有实际意义。通过与实测资料比较,认为垂直湍流系数模式要比常垂直湍流系数模式更为合理。 相似文献
104.
105.
A higher-order non-hydrostatic model in a σ-coordinate system is developed. The model uses an implicit finite difference scheme on a staggered grid to simultaneously solve the unsteady Navier-Stokes equations (NSE) with the free-surface boundary conditions. An integral method is applied to resolve the top-layer non-hydrostatic pressure, allowing for accurately resolving free-surface wave propagation. In contrast to the previous work, a higher-order spatial discretization is utilized to approximate the large horizontal pressure gradient due to steep surface waves or rapidly varying topographies. An efficient direct solver is developed to solve the resulting block hepta-diagonal matrix system. Accuracy of the new model is validated by linear and nonlinear standing waves and progressive waves. The model is then used to examine freak (extreme) waves. Features of downshifting focusing location and wave asymmetry characteristics are predicted on the temporal and spatial domains of a freak wave. 相似文献
106.
Wind and waves are major forces affecting the geomorphology and biota in coastal areas. We present a generally applicable method for measuring and calculating fetch length, fetch direction and wave exposure. Fetch length and direction, measured by geographic information system-based methods, are used along with wind direction and wind speed data to estimate wave height and period by applying forecasting curves. The apparent power of waves approaching the shore, used as a proxy for wave exposure, is then calculated by a linear wave model. We demonstrate our method by calculating fetch lengths and wave exposure indices for five areas with varying exposure levels and types of meteorological conditions in the Finnish Archipelago Sea, situated in the northern Baltic Sea. This method is a rapid and accurate means of estimating exposure, and is especially applicable in areas with geomorphologically varying and complicated shorelines. We expect that our method will be useful in several fields, such as basic biogeographical and biodiversity research, as well as coastal land-use planning and management. 相似文献
107.
In this paper, the theoretical analysis and experimental studies are employed to investigate the reflection characteris-tics of partial standing waves caused by wave overtopping and sloping top of structures. Based on the principle of conser-vation of wave energy flux, the third-order Stokes wave theory is used to formulate the reflection coefficient at wave overtopping; the calculation results are regressed into an applied expression. A series of experiments of wave reflection for a vertical-wall structure with chamfered and overhanging upper sections are carried out to investigate the influence of top slope on wave reflection. The regularity of variation of wave reflection in this case is analysed based on the experimental results. 相似文献
108.
109.
一个基于TOPEX卫星极端海面风速预测的海洋地理信息系统 总被引:4,自引:1,他引:4
在基于 TOPEX卫星数据建立全球极端海面风速预测模型的基础上 ,开发出用于极端海面风速预测和可视化预测结果的海洋地理信息系统 (MGIS)。并论述全球极端海面风速预测的意义和 MGIS在预测过程中的重要性及必要性 ;给出全球极端海面风速预测的统计模型 ;简述极端海面风速预测海洋地理信息系统的结构、工作流程和功能 ;同时 ,对系统的预测结果进行初步分析 相似文献
110.
The analytical method (AM) for separation of composite waves is presented based on the Hilbert transform. It is ap-plicable to both regular and irregular trains of waves. The wave data series measured with two wave gauges in the experi-ments are separated into two series of incident and reflected waves. Then, the reflection coefficient can be easily ob-tained. The arrival of reflected waves can also be detected for improveraent of the accuracy of the reflection coefficient. The reflection performance of the physical model can be estimated exactly without calculation of wave height and phase difference. Numerical samples developed to test the method are proved to be accurate. Physical experiments are conduct-ed and compared with Goda s method and satisfactory results are obtained. 相似文献