摘要
将湍流研究中已得到有效应用的局域小波能谱概念引入到风浪研究。分析了实验室不同风速下风浪的局域小波能谱。结果表明，局域小波谱峰值存在着显著的涨落，涨落的方差随风速的增加而增大。这不仅体现了风浪的局域结构，还意味着通常风浪谱的应用中除了要考虑平均意义下的频谱峰值外，还必须考虑局域小波谱峰值的涨落方差。
This study is concerned with the physical interpretations for the statistical uncertainty of the spectral peak energy and peak frequency of the Fourier frequency spectrum. The local wavelet energy spec- trum, based on the wavelet transform, is introduced to analyze the wind wave data obtained in a wind wave channel. It is shown that wave energy exhibits localizations both in scale (frequency) and physical space (time) , which implies energy intermittency-the energy at a given frequency may not be evenly distributed in the whole time. Especially , the peak energy and the corresponding peak frequency of a local wavelet energy spectrum have significant fluctuations as time evolves. Such intermittency and fluctuations give appropriate in- terpretations for the above mentioned statistical uncertainty.
出处
《海洋学报》
CAS
CSCD
北大核心
1998年第3期1-5,共5页
基金
国家自然科学基金
国家自然科学重点基金
青岛海洋大学物理海洋实验室开放基金
关键词
局域结构
小波变换
小波能谱
涨落
风浪
波谱峰
Local wavelet energy spectrum, local spectral peak, peak frequency
