A laboratory study of directional spectra with maximum likelihood method─I Developing wind wave

作     者：Zhao Dongliang Masuda Akira Wen Shengchang and Guan Changlong 

作者机构：Institute of Physical Oceanography Ocean University of Qingdao Qingdao 266003 China Research Institute for Applied Mechanics Kyushu University Kasuga 816 Japan 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：1999年第18卷第1期

页      面：59-74页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

主　　题：Directional spectrum maximum likelihood method wind wave 

摘      要：From measurements by a circular array consisting of 18 wave gauges in a large wave tank, directional spectra of wind-generated waves in deep water are systematically determined by using maximum likehood *** investigations reveal that the angular spreading of the wave energy is consistent with cos2s(θ/2) proposed by Longuet-Higgins et al. (1963, Ocean Wad Spectra,11~136), if the bimodal distributions of wave energy are not taken into account. Bimodality occurring on higher frequency than peak frequency is too rare to affect our whole results. Surprisingly, a much broader directional spreading than that of the field, which is interpreted by the strongly nonlinear energy transfer because of the very young waves in laboratory, is found. The parameter s depends on frequency in the same way as observed by Mitsuyasu et al. (1975, Journal of Physical Oceanography, 5, 750~760)and Hasselmann et al. (1980, Journal of physical Oceanography, 10, 1264~1280) in the field, and the relationship between the four nondimensional parameters sm, fo, b1 and b2, determining the directional width, and (corresponding to the inverse of wave age) are given respectively. The observed distributions are found to agree well with the suggestion of Donelan et al. (1985, Philosophical Transaction of Royal Society of London, A315, 509~562) when applied to field waves.