摘要
本文研究周期大于9天的超低频振动，这类振动与水位长期变化密切相关。海洋水位长期变化是地球自转、气候变异和海洋水量平衡的重要指标，也是大尺度海气互相作用、气候过程、海洋动力学过程和海洋水文因子综合作用的结果。
In this paper, the pole tide and long period species contained in the nodal terms are separated by spectral analysis of a set of data from Qingdao.The length of such a set is greater than the lunnar nodal period. The amplitudes and the phases of nodal constituent,seminodal constituent and other long period constituents are obtained.The results indicate that the Sa, Msf,Ssa and pole tide are the most important compared to other Ultra-Low-Frequency constituents. The changes of the mean sea level for last 30 years are also dealt with.
