基于Swarm卫星磁测数据的全球多场源地磁场建模
Global geomagnetic field modeling based on Swarm Alpha magnetic field measurement
杨艳艳 1泽仁志玛 1申旭辉 2王婕 1黄建平 1王桥 1鲁恒新1
作者信息
- 1. 应急管理部国家自然灾害防治研究院,北京 100085
- 2. 中国科学院国家空间科学中心,北京 100190
- 折叠
摘要
全球多场源地磁场模型因其可同时描述场源多、使用方便等优点在很多行业中得到了应用.本文基于高精度磁测卫星Swarm A自发射以来的九年标量和矢量观测数据,利用球谐分析方法,同时实现主磁场及其变化、岩石圈磁场和磁层外源场模型系数的反演.其中内源场球谐截止阶数70阶,对应空间分辨率为571 km;主磁场变化求解至13阶,采用6阶B样条函数描述,可实现主磁场长期变化、长期加速度等的计算;外源场球谐截止阶数2阶.统计结果表明最终模型拟合rms为3.29 nT.为了对模型结果开展评估,先后利用综合场模型CM6和CHAOS-7对功率谱以及各场源全球分布开展了对比,结果表明该模型与CM6和CHAOS-7模型结果在趋势和量值上均十分接近,其中主磁场、岩石圈磁场和磁层外源场与CHAOS-7模型典型残差分别在5 nT、1 nT和2 nT以内.此外,基于Swarm A卫星模型,我们还分析了 2014和2023年的全球主磁场变化特征,对全球岩石圈磁异常和外源场分布规律进行了展示和总结.通过本项工作可以实现多场源模型系数的同步解算,为相关行业应用提供技术支撑.
Abstract
Global multi-sources geomagnetic field models have been applied to many fields because of their superiority in simultaneously describing many sources and convenience of use.In this work,nine year's high-resolution magnetic field data from Swarm Alpha satellite are used to develop a global geomagnetic field models including the main field and its variation,lithospheric field and magnetospheric field.During the modeling,the internal field is solved up to spherical harmonic degree and order 70,corresponding to wavelength of 571 km at the Earth's surface;the main field variation is described by 6 0rder B-spline,which can be used to the estimation of the main field secular variation,secular acceleration and so on;the external field is solved up to spherical harmonic degree and order 2.The final modeling rms is 3.63 nT.To evaluate the model,the power spectrum and global features is comprehensively compared with CM6 and CHAOS-7 geomagnetic field model.It indicates that these models are comparable in trend and magnitude.Specially,the typical residual field between our model and CHAOS-7 is respectively within 5 nT,1 nT and 3 nT for main field,lithospheric field and external field.Based on our model,the global changing of the main field since 2014 has been analyzed and the main characteristics of the lithospheric field and magnetospheric field are also shown.
关键词
卫星磁测/地磁场模型/主磁场/岩石圈磁场/外源场Key words
Satellite magnetometry/Geomagnetic field model/Mian field/Lithospheric field/External field引用本文复制引用
基金项目
国家自然科学基金(42274214)
国家自然科学基金(41904134)
国家自然科学基金(42004051)
亚太二期地震电离层扰动五期龙计划项目(59236)
出版年
2024
NETL
NSTL
万方数据