Fluctuations of peak energy and peak frequency of local wavelet energy spectrum for wind waves

Ｆｌｕｃｔｕａｔｉｏｎｓ　ｏｆ　ｐｅａｋ　ｅｎｅｒｇｙ　ａｎｄ　ｐｅａｋ　ｆｒｅｑｕｅｎｃｙ　ｏ　ｌｏｃａｌ　ｗａｖｅｌｅｔ　ｅｎｅｒｇｙ　ｓｐｅｃｔｒｕｍ　ｆｏｒ　ｗｉｎｄ　ｗａｖｅｓTXＦｌｕｃｔｕａｔｉｏｎｓｏｆｐｅａｋｅｎｅｒｇｙａｎｄｐｅａｋ...     

A Study on the Spectral Form of Nearshore Water Waves

- The spectral form of wind waves is investigated based on the ocean wave data observed at three nearshore stations of Taiwan. In this study, the generalized forms of Pierson-Moskowitz spectrum and JONSWAP spectrum are used to describe the local wave spectrum by selecting suitable spectral form parameters. It is shown that, at a specific site, the similarity of wave spectral form exists. Thus it is possible to use a representative spectral form for a given nearshore region to describe the wave spectrum at this nearshore. On the other hand, the effects of relative water depth on spectral form are examined. The feasibility of two spectral models in finite water depth is evaluated by using the same field wave data.     

碱厂废水光谱特性实验研究

该文报道碱厂废水随浓度变化的光谱实验。分析碱厂废水的光谱特征 ,并与相同浓度的海水悬浮泥沙水体的光谱进行比较 ;确定该废水特征波长为 50 1.3nm。根据光谱实验结果 ,结合当前已有的水色传感器的资料 ,选择两个卫星传感器波段 :Sea WIFS第四频道 (497.2～ 52 1.6 nm)和TM第二频道 (518.9～ 6 0 0 .2 nm) ;利用数字对 (R,c) ,建立了反射率与该污染水体浓度间的相关模式。为遥感技术大面积、快速地监测碱厂废水污染水体提供理论依据。     

Observations and Estimations of Directional Spectrum of Sea Waves

The directional spectrum is one of the basic characteristics of sea waves. The observations of directional spectrum of sea waves were successfully conducted at platform Bohai 8 during 1991 and 1992 using a wave gage array for the first time in China. Based on the field data, the directional spectrum which depends on the wave growth is given in this paper. Before observations, the effects of the type of gage array, the distance between the gages and the platform itself on the measured results and the precision of some methods for estimating the directional spectrum were investigated and compared with the methods of numerical simulations and model tests of multi-direcitonal irregular waves. This ensures the quality of the observations and estimations of the directional spectrum.     

长江河口径流与盐度的谱分析

根据大通水文站的流量和引水船站的盐度系列资料,应用谱分析方法研究长江口径流、盐度的变化规律及两者的相互关系.分析表明,长江口径流存在4～8a,2～3a,1.5a,1a,30～60d及20d的及化周期;盐度存在5～10a,2～3a,1.5a,1a,0.5a,40～50d,26～30d,14～15d7～8d及3.5d的变化周期.径流和盐度的谱结构在各水文年基本一致,均以1a周期变化占优势,但盐度谱结构在高频部分较径流的谱结构具有更大的振荡.盐度与流量的5～10a,2～3a,1.5a,1a的周期振动上存在高相关.径流对盐度变化的影响主要体现在低频部分.在低频变化中表现为盐度变化滞后于径流变化,在高频带呈同步变化.     

贝叶斯统计方法在海浪方向谱研究中的应用

较详细介绍了贝叶斯统计方法在海浪方向谱估计中的应用,指出先验分布的不同对估计结果没有影响,由于均匀分布与最大熵原则相对应,使其具有某种特殊性.数值模拟表明贝叶斯方法对双峰方向分布估计的有效性,将其应用于黑海实测资料,证明双峰方向分布的出现依赖于估计方法分辨力的大小,而用最大似然法得到的双峰方向分布值得怀疑.最后给出出现双峰方向分布的一种可能物理解释.     

风浪槽内风浪外频谱谱形的一些特征

利用实验室风浪槽内测得的波面序列资料估计风浪外频谱。通过与实测风浪内频谱的比较,研究实测风浪外频谱的谱形特征,探讨海浪外频谱与内频谱的相似性问题。此外,还检验一种理论海浪外频谱。     

A proposed directional function and wind-wave directional spectrum

Ａｐｒｏｐｏｓｅｄｄｉｒｅｃｔｉｏｎａｌｆｕｎｃｔｉｏｎａｎｄｗｉｎｄ－ｗａｖｅｄｉｒｅｃｔｉｏｎａｌｓｐｅｃｔｒｕｍ￥ＷｅｎＳｈｅｎｇｃｈａｎｇ；ＷｕＫｅｊｉａｎ；ＧｕａｎＣｈａｎｇｌｏｎｇ；ＳｕｎＳｈｉｃａｉａｎｄＺｈａｎｇＤａｃｕｏ（Ｒｅｃｅｉ...     

Application of sequency spectral method to ocean and atmosphere data analysis

I~IOWIn recent years, with the development of the nonlinear science, eSPecially the sea surface remote sensing measurement technology and the probing Of the modern naval science, the effects ofnonlinear coupling interaction have gradually drawn universal attention.But due to the limitation of claSSical frequency spectral method (Bracewell, 1990), it is difficult to characterize the nonlinear coupling inforTnation at higher frequency band. Thus, there havereconed the fundamental pwhleln to …     

海浪外观波数谱与谱宽度最优确定

本文将外频谱转化为外观波数谱并设计了计算处理格式,提出了一种谱宽度参量的优化方法,为进一步研究海浪特征资料提取谱值和应用奠定基础。数值试验验证了此方法的可行性,但在高海况下风浪过程复杂,优化出的谱宽度偏大,外观谱解析形式需进一步改进