旋转层化二维海洋波动连续谱的波包特征分析

对旋转层化二维海洋波动中重力惯性波和涡旋波连续谱波包的结构以及演变特征作了计算和分析,并得到以下结论:这两类波动的结构与演变各不相同。连续谱波包的演变不但依赖基本场的分布,而且还依赖初始扰动的结构。根据初始场的不同,扰动可衰减,也可先增长、再衰减,有时增长还很大,但其最终是衰减的。连续谱波包的结构随时间变化,然而构成该波包的连续谱其结构则不随时间变化,这是两者的最大差异。连续谱波包的上述演变特性表明,在有限时段扰动的演变中连续谱是不能被忽略的,在海洋波动演变中连续谱和离散谱的作用均须予以考虑和重视。

Analysis of continuous spectrum wave packet in rotational-stratification two-dimension ocean

The structure and evolvement of continuous spectrum wave packet is studied for two-dimensional vortex wave and inertial-gravitational wave in the rotationalstratification ocean.The results show that the two kinds of wave are different in their structure and evolvement.The evolvement of continuous spectrum wave packet depends not only on the distribution of basic field but also on the structure of initial disturbance field.The disturbance may decrease,or increase at first and then decrease,sometime the increase is large,but it is finally absorbed by the basic flow.The structure of the continuous spectrum wave packet goes with time,nevertheless the structure of the continuous spectrum which composes the wave packet does not go with time,which is the largest difference between the continuous spectrum and its wave packet.In sum,all the facts show that the evolvement of continuous spectrum wave packet can not be neglected in limited time.Both the continuous spectrum and the discrete spectrum all needs to be considered and studied.