Maximum entropy spectral analysis for annual maximum tide levels time series of the Changjiang River Estuary

In this study, Maximum Entropy Spectral Analysis (MESA) is employed to analyze the cryptic periods of annual maximum tide levels at Tiansheng Port station in the Chanjiang River estuary, China. The subsection technique is used to determine whether the cryptic periods obtained have consistency and stability. Three cases are investigated, namely the original data series, the linear polynomial trend eliminated series and the quadratic polynomial trend eliminated series. The results show that the cryptic periods obtained by MESA vary enormously, and the first cryptic period calculated is not consistent or stable. The analysis indicates that there is no clear cryptic period in either the original data series or the de-trended series, and thus the hypothesis that the annual maximum tidal levels occur as random events, has been validated. MESA is easy to use to obtain stochastic characteristics. Thus spectral analysis and computations related to stochastic model development may be integrated by using MESA.