TIME-FREQUENCY ANALYSIS OF THE INTER-SEASONAL VARIATIONS OF CHINA-NEIGHBORING SEAS LEVEL
中国近海海平面季节尺度变化的时频分析

The fast Fourier Transform (FFT) and the Continuous Wavelet Transform (CWT) are used to analyze the basic features of inter-seasonal variations of the sea level in China Seas from tide gauge records and Topex/Poseidon altimetry data (from October of 1992 to September of 1998). The results indicate that the sea level variations over the Yellow Sea and the East China Sea are similar, which have two strong oscillatory signals with the periods of annual and about 60 days, annual and semiannual signals are prominent in the South China Sea. The sea level variations show significant differences at inter-seasonal scales between shallow sea and deep-sea.