摘要
本文运用小波变换技术,通过分析历史地磁场模型gufml（时间跨度从1590～1990年）,考察主磁场长期变化场（B场）的周期性.结果表明,B场总磁极强度存在三个主要的周期分量：稳定的30年周期,在偶极子场的赤道分量g1/1和非偶极子场中较常见;频散的准50年周期,主要是由轴向偶极子分量g0/1贡献的,此外,四极子场也有贡献;世纪尺度的110年周期,其强度会发生变化,主要来源于偶极子场的赤道分量以及八极子场.
In this paper, the technique of wavelet transform is applied to analyze the gufm1 models during 1590~1990 A.D., for detecting the periodicities in the secular variations of the main geomagnetic field. Our analysis suggests that there are three principal periodic components in the total Pole-strength of B field： a stable 30-year periodic component which is mainly seen in the equatorial component g11 of the dipole field, and it is also generally seen in the non-dipole field; second, a dispersive quasi 50-year periodic component, typically contributed by the axial component of the dipole field g01, and the quadrupole also has a definite contribution; the last one is an intensity varying 110-year periodic component on centennial time scale, which seems to be from the equatorial component of the dipole field, and the octupole field also has a contribution.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第4期904-911,共8页
Chinese Journal of Geophysics
基金
国家重点基础研究发展计划(973计划)(2008CB425704)
国家自然科学基金项目(40874089)资助
关键词
主磁场
长期变化
小波分析
周期性
Main geomagnetic field, Secular variation, Wavelet analysis, Periodicity
