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利用最新的4种高精度全球模型——CM4、NGDC-720、EMM2010与MF7分别建立了中国大陆地区岩石圈磁场,并进行了对比分析,并通过Lowes-Mauersberger功率谱技术展示了常用的10种全球模型的岩石圈磁场功率谱.以EMM2010模型为例,分析表明其岩石圈磁场功率谱变化趋势可以分为5个主要阶段.16~65阶缓慢增加;66~120阶加速增加;121~220阶为平稳阶段,功率达到了最大值;221~670阶缓慢下降;671~719阶缓慢增加.对上述5个阶段的系数绘制并分析了其在中国大陆地区的岩石圈磁场分布,结果表明16~65阶与66~120阶系数构成了岩石圈磁场的主要部分.121~719阶系数对应的磁场非常凌乱,都随着纬度的上升而增强,121~220阶系数对应了岩石圈磁场的极值强度或分布.随着截断阶数的增加,岩石圈磁场的正负分布面积逐渐减小且凌乱.相比CM4模型,EMM2010能表达更多小尺度的磁异常信息.
Using the latest four global high-precision models --CM4, NGDC-720, EMM2010 and MF7, the lithospheric magnetic fields in the Chinese mainland have been established and compared. The low-maizersberger power spectrum has been used to demonstrate the commonly used 10 kinds of lithospheric magnetic fields. Global model lithospheric magnetic field power spectrum. Taking EMM2010 model as an example, the analysis shows that the lithospheric magnetic field power spectrum trend can be divided into five main stages: 16 ~ 65 steps increase slowly; 66 ~ 120 steps accelerate increase; 121 ~ 220 The order is stable, and the power reaches the maximum value. The order of 221-670 decreases slowly and the order of 671-719 increases slowly. The distribution of the lithospheric magnetic field in the above five stages is plotted and analyzed. The results show that ~ 65th order and 66 ~ 120th order coefficients constitute the main part of the lithospheric magnetic field.The magnetic fields corresponding to the 121 ~ 719 order coefficients are very messy, both increase with the latitude, and the 121 ~ 220th order coefficients correspond to the polarities of the lithospheric magnetic field With the increase of truncation order, the positive and negative distribution area of lithospheric magnetic field decreases and becomes messy.Compared with CM4 model, EMM2010 can express more small-scale magnetic anomaly information.