基于泰勒多项式模型的1960—2000年中国大陆各年代磁异常场差异  

Differences of geomagnetic anomalous field over Chinese mainland and its adjacent areas during 1960−2000 based on Taylor polynomial model

作　　者：杨雨静 冯彦 Yang Yujing;Feng Yan(Reading Academy,Nanjing University of Information Science&Technology,Nanjing 210044,China;School of Atmospheric Physics,Nanjing University of Information Science&Technology,Nanjing 210044,China;State Key Laboratory of Space Weather,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]南京信息工程大学雷丁学院,中国南京210044 [2]南京信息工程大学大气物理学院,中国南京210044 [3]中国科学院空间天气学国家重点实验室,中国北京100190

出　　处：《地震学报》2023年第2期302-314,共13页Acta Seismologica Sinica

基　　金：国家自然科学基金(42250103,41974073,41404053);科工局民用航天预研项目(D020308);2021年度中国科学院空间天气学国家重点实验室开放课题;月球与行星科学国家重点实验室(澳门科技大学)开放课题(澳门科学技术发展基金:119/2017/A3);2022年度南京信息工程大学雷丁学院创新创业训练计划联合资助。

摘　　要：基于1960.0,1970.0,1980.0,1990.0和2000.0年的中国大陆地区实测地磁数据,采用泰勒多项式展开建立了一个中等尺度的低空间分辨率的地壳磁异常模型,结合第四代地磁场综合模型CM4绘制了各年代的磁异常场分布图,并将所有实测点归算至2000.0年以分析磁异常的整体分布,而后通过最新开发的综合地面磁测数据及航空磁测的三维曲面样条模型研究各年代磁异常的差异。结果显示:泰勒多项式模型的北向分量X的磁异常强度随时间逐渐降低,分布呈向西南收缩趋势;东向分量Y的磁异常呈正值区向西部移动、负值区逐步占据优势的趋势;垂直分量Z的磁异常以负值为主,形态较为稳定,说明该分量不易受到其它因素的干扰。对于归算后磁异常的整体分布,X向和Z向分量、总强度F、垂直分量H几乎均为负值,与CM4模型存在一定的差异。由于数据的相似性,总强度F的分布与3DSS模型有一些相似特征,但后者可反映更多的中小尺度磁异常信息。三种模型存在的差异主要来自数据数量、位置和建模方法的不同。This study adopts the geomagnetic measurements of the Chinese mainland in 1960.0,1970.0,1980.0,1990.0,2000.0,and the Taylor polynomial model to build up a medium-scale crustal magnetic anomaly model with low spatial resolution,associated with the fourth-generation geomagnetic comprehensive model(CM4).The figures of the anomaly field are drawn.The whole trends of the field are studied by putting all measurements into 2000.0.The differences in anomalies among different epochs have also been analyzed by the newest three-dimensional surface spline(3DSS)model derived from all available ground and aeromag-netic data.Results show that the intensity of the northward component X decreases with time,and its distribution shrinks to the southwest;the positive area of eastward component Y gradu-ally moves to the west,and the negative area gradually occupies most of Chinese mainland;the distribution of vertical component Z is stable and is mainly negative in the study area,which implies that other factors do not likely influence the radial component.For the overall distribu-tion of magnetic anomalies,components X,Z,total intensity F and horizontal component H are almost negative,which differs from CM4.Regarding the data consistency,the distribution of F has some similar features to the 3DSS model,which can illustrate more middle and small wavelength structures of the anomaly field.Large differences among the three models mainly come from the different measurement numbers,locations,and modeling theories.

关 键 词：地磁场 磁异常场 泰勒多项式模型 三维曲面样条模型 第四代地磁场综合模型 

分 类 号：P318.4[天文地球—固体地球物理学]