【摘要】 用经验正交函数分析方法,对中国近海14年多的测高海平面同化格网资料进行分析,给出了黄海、东海和南海各海平面变化主要主成分的空间变化和时间变化特征.用标准Morlet小波变换方法分析了各海区主成分时间变化序列的时频特征.分析结果表明,各主成分的空间分布特征与当地的海洋环流或洋流特征相对应.时频分析结果显示,中国近海海平面变化的显著周期主要为年周期信号.其次,黄海和东海还显示准2个月的非稳态信号,东海和南海具有较显著的半年周期信号,东海半年周期信号的能量不稳定.此外,在南海及台湾东部海域,首次发现存在较为显著的准540天周期信号,其动力学机制目前尚不明确.坎门和西沙验潮站资料的时频特征分析也验证了该信号的存在.最后本文给出了中国近海海平面在1993～2007年间的平均上升速率和其区域分布特征.更多还原

【Abstract】 Merged altimetry sea level anomaly data over China seas for more than 14 years is analyzed using the Empirical Orthogonal Function method. The spatial and temporal characteristics of sea level variability over Yellow Sea (YCS), East China Sea (ECS) and South China Sea (SCS) are presented, respectively. Using normal Morlet wavelet transform, we analyzed the time-frequency characteristics of the main principal components. The results indicate that the spatial models of the principal components correspond to the circulations or oceanic currents in China seas. The prominent periodic signals in Yellow and East China Seas are the annual and two month cycles. The annual and semi-annual period signals are prominent in the East China Sea and South China Sea. But the semi annual signal in East China Sea is instable. More importantly, a prominent quasi 540d signal is first identified in the East China Sea and South China Sea. The result of the tide gauge data of Xi Sha also proved that this signal existed.更多还原