The energy density spectrum and secular variation of the Earth s main magnetic field on the surface of the earth during 1690～2000 were calculated and analyzed according to the models of Jeremy Bloxham and Andrew Jackson and the eighth generation of International Geomagnetic Reference Field.
根据BJ地磁场模型和第 8代国际地磁参考场模型，计算并分析了 16 90～ 2 0 0 0年期间地球表面主磁场和分量的能量密度谱及其长期变化。
The spherical cap harmonic models of the geomagnetic field and its secular variation can better express the spatial-temporal variation of the geomagnetic field in China. The root mean square deviations of the geomagnetic model are 104.4nT for X, 103.3nT for Y and 123.9nT for Z.
中国地磁场冠谐模型能更好地表示我国地磁场的时空变化，地磁场模型的均方偏差为：104.4nT，103.3nT，123.9nT。
The quadrupole field (n=2) is the most significant one of the geomagnetic secular variation in the 20th century. The Gauss series of the geomagnetic secular variation is converged slower than that of the main field. Using the method of tracing the change of the position of the anomaly focus, it is found that there are 5 anomalies in the chats of Z of the secular variation of the nondipole field. Their drifting is not consolidate in a few degrees. But they are drifting westward basically.
20世纪地磁长期变化场的四极子（n=2的高斯系数所表示）变化最为显著，与主磁场相比长期变化场的球谐级数收敛较慢，利用追踪异常焦点位置随时间的变化的方法，发现地磁非偶极子长期变化场的垂直分量Z的等值图上有五大异常，其漂移情况不太统一，但是基本上是西向漂移。
According to these secular variation models, the absolute value data of three components at 426 sites for 1936.0 are reduced to 1940, 1930, 1920, 1910 and 1900. These data have laid a solid foundation for calculating the geomagnetic field models for these 5 epoches.
根据这些长期变化模型，将1936.0年426个点的三分量绝对值数据归算至1940193019201910年和1900年，从而为计算这5个年代的地磁场模型奠定了坚实的基础。
The magnetically quiet day and magnetically disturbed day as well as the low point time at the magnetically quiet day are analyzed by the annual variation and secular variation of geomagnetic Z component datum observed at Changli and Hongshan Stations.
利用昌黎、红山等台站的地磁Z分量日变资料，分析了磁静日幅度、磁扰日幅度和磁静日低点时间的年变化与长期变化，结果年变化和长期变化都非常明显。
Processing of secular variation and disturbance related to marine geomagnetic diurnal variation correction
与海洋地磁日变改正有关的长期变化和磁扰的处理
IGRF (International Geomagnetic Reference Field) are the models of geomagnetic main field and secular variation. The IGRF errors are from neglecting external field, truncation level of the spherical harmonic series, observatory distribution, measurement, and neglecting the crust geomagnetic anomalies.
IGRF（国际地磁参考场）是有关地球主磁场与长期变化的模型，IGRF的误差主要来源于：忽略外源场、球谐级数的截断、台站分布的不均匀、测量、忽略地壳磁异常场等。
Jackson (BJ) and the International Geomagnetic Reference Field (IGRF), the distribution of geomagnetic field and its secular variation going back to 1690 year are calculated and analyzed theoretically.
模型（BJ）和国际地磁参考场模型（IGRF）从理论上计算并分析了1690年以来地磁场能量在地球内部的分布及长期变化。
Using International Geomagnetic Reference Field (IGRF), correlation of geomagnetic secular variation and decadal timescale changes in the length of day (LOD) are calculated and analyzed for 1900~2000. The torque of core-mantle electromagnetic coupling is calculated.
分析1900～2000年期间地磁长期变化和日长变化10年尺度波动的相关性，估算了核幔电磁耦合力矩，并与国外一些研究者的结果进行了对比。
According to the observation data at Urumqi geomagnetic station since the historic times, we sum up and analyse the laws of the geomagnetic secular variation, geomagnetic short period variation and the activity of magnetic storm.
根据乌鲁木齐地磁台有史以来的地磁观测资料，对该地区地磁场的长期变，短期变及其磁暴活动规律进行了总结分析。
With geomagnetic field model records, several kinds of secular variation of geomagnetic dipole moment and the position of the geomagnetic north pole during the year 0~2000 A. D are calculated and analyzed.
利用地磁场模型资料，计算和分析了公元0～2000年的地磁场偶极子磁矩和地磁北极位置的长期变化。
The results show that there is lag correlation between change rate of dipole magnetic moment M & and the changes in the length of day. The geomagnetic secular variations lag LOD variation by approximately 5~10 years.
结果表明，地磁偶极矩的变化率M&与日长10年尺度波动存在时滞相关，地磁偶极矩变化比日长变化滞后大约10a；
Study of secular variation of geomagnetic field by means of VGP
用虚地磁极（VGP）方法对地磁场随时间变化的研究
Theory, observation and application of the geomagnetic polarity reversal and secular variation, magnetostratigraphy;
地磁场倒转和长期变的理论、观测和应用以及磁性地层学；
Effect of high-degree harmonics in the IGRF models on secular variation of the geomagnetic field
国际参考地磁场模型中高阶球谐项对地磁场长期变化的影响
Spherical cap harmonic analysis of the geomagnetic field and its secular variation in China for 2000
2000年中国地磁场及其长期变化冠谐分析
The main geomagnetic field, B, and its secular variation, , originate from same dynamo process in the outer core.
地球主磁场B和它的长期变化.B都起源于地球外核的磁流体发电机过程，但是，它们的空间结构和时间演化特征却有很大差异。
The results show that there is lag correlation between change rate of dipole magnetic moment M & and the changes in the length of day. The geomagnetic secular variations lag LOD variation by approximately 5 ~ 10 years.
结果表明，地磁偶极矩的变化率M&与日长10年尺度波动存在时滞相关，地磁偶极矩变化比日长变化滞后大约10a；