HHT技术探测Slichter模三重谱线的研究

探测Slichter模态三重分裂可有效约束内核密度、内核半径及内外核边界密度跳跃。虽然Smylie(1992)声称探测到了Slichter模态三重分裂,但至今未被国际学术界公认。本文结合一个实验算例,阐述了Hilbert-Huang变换(HHT)分析方法的核心思想,并将该方法应用于探测Slichter模三重分裂谱线的研究。我们选取了全球分布的8个台站连续记录两年的小时间隔超导重力数据,进行了潮汐和气压改正后,将它们叠加获得重力残差;然后对重力残差作HHT分析,得到能量谱,进而选出了12种可能的谱峰组合,其中两组结果与Smylie的结果很接近,且本文得到的谱峰分裂相比于Smylie的结果具有更好的对称性。

Detecting the triplet of Slichter mode based on HHT technique

Observations of the Slichter mode triplet have effective constraint on the density and radius of the inner core,as well as the density jump at the inner core boundary.Smylie(1992)declared that the triplet of the Slichter mode was detected,but his results have not yet been accepted by most scientists.In this paper,the authors elaborated the core idea of the Hilbert-Huang Transform(HHT)technique via an experimental example analysis,and then used this analysis technique to detect the Slichter mode triplet.They chose continuous two-years long one-hour-interval superconducting gravity(SG)data recorded at eight stations distributed globally,and superimposed them after tide and pressure correction to obtain the gravity residual.Then,they applied the HHT analysis technique to the gravity residual series to obtain the energy spectrum,from which they found 12 combinations of the triplet spectral peaks as possible candidates of the Slichter mode triplet.Especially,two triplets of them were very close to Smylie's result.It was noted that,comparing with Smylie's result,the results have more symmetrical spectral splitting pattern.