极移振幅主要周期分量的时变特征  

Time-variation of periodic components of polar motion amplitude

作　　者：韩永志[1] 马利华[1] 尹志强[1] 

机构地区：[1]中国科学院国家天文台

出　　处：《地球物理学进展》2006年第3期798-801,共4页Progress in Geophysics

基　　金：国家自然科学基金(10373017)资助

摘　　要：用JPL近年发布的地极坐标序列求得1893?1998年间极移的振幅序列,用最大熵谱分析方法求得了该资料序列包含的一些周期的参数,并利用小波变换方法分析讨论了其中的主要周期的变化.结果表明,极移振幅变化中存在着约6.5年和约40年的主要周期,且它们均具有一定程度的时变性.因此,在研究讨论极移与一些地球物理现象和自然灾害现象的关系时,应特别注意极移振幅中主要周期的时变特征.The data series of the polar motion amplitude in 1893.0-1997.95 was obtained from coordinates of the Earth＇s pole that are published by JPL in recent years. The parameters of the variational periods of the data series were got by the Maximum Entropy Power Spectrum Analysis. The authors analyzed and discussed the change of the periods using wavelet transform. The result shows that there are main periods in the amplitude variation, such as about 6.5-year and 40-year, and the periods have the character of variation with time. Thus, the time-variation of main periods of the polar motion amplitude should be paid more attention when the relationship between polar motion and some geophysical phenomena and natural disasteris is studied.

关 键 词：地极移动 谱分析 振幅 小波变换 时变 

分 类 号：P35[天文地球—空间物理学]