Nonlinear processes of energy transfer from traveling hurricanes to the deep ocean internal wave field
Nonlinear processes of energy transfer from traveling hurricanes to the deep ocean internal wave field
复制标题
DOI：
10.1029/97jc00588
复制
发表时间：
1997-06
影响因子：
--
通讯作者：
Y. Niwa;T. Hibiya
中科院分区：
文献类型：
--
作者：
Y. Niwa;T. Hibiya
本文利用一个三维多层数值模式，研究了一个沿海洋匀速运动的飓风产生的大尺度内波。结果发现，在飓风尾流中激发出两种不同的内波，即可以用线性理论解释的近惯性波和由非线性效应产生的频率为200和300（200是飓风路径纬度处的惯性频率）的超惯性波。我们特别关注的是频率为200和300的超惯性波，因为这些内波被认为是深海小尺度混合的有效能源。这些超惯性波主要具有低垂直模式结构，并满足背风波的色散关系。特别是在远离飓风路径的地区，双惯性频率波变得比近惯性波大。通过计算超惯性波的双谱，研究了引起超惯性波产生的非线性共振三波组，结果表明，最低垂直模双惯性频率波是通过高垂直模近惯性波之间的非线性相互作用有效产生的。
Generation of large-scale internal waves by a hurricane traveling over the ocean with a uniform velocity is investigated by using a three-dimensional, multilevel numerical model. It is found that two distinctive kinds of internal waves are excited in the wake of the hurricane, namely, near-inertial waves, which can be explained based on the linear theory, and superinertial waves with frequencies 2ƒ0 and 3ƒ0(ƒ0 is the inertial frequency at the latitude of the hurricane track), which are generated through nonlinear effects. Our special attention is directed to the superinertial waves with frequencies 2ƒ0 and 3ƒ0 because these internal waves are considered to be efficient energy sources for small-scale mixing in the deep ocean. These superinertial waves predominantly have low-vertical-mode structures and satisfy the dispersion relation for lee waves. In areas away from the hurricane track, in particular, the double-inertial frequency waves become larger than the near-inertial waves. The nonlinear resonant triads causing the generation of such superinertial waves are examined by calculating the bispectrum, which clearly shows that the lowest-vertical-mode double-inertial frequency wave is generated efficiently through the nonlinear interaction between the high-vertical-mode near-inertial waves.