基于10ka尺度的区域非偶极子磁场变化的研究  

Regional variation studies of non-dipole magnetic field in 10ka scale

作　　者：段泊岩 冯彦 唐艺嘉 王安琦 汤博雅 杨雨静 DUAN BoYan;FENG Yan;TANG YiJia;WANG AnQi;TANG BoYa;YANG YuJing(NUIST Reading Academy,Nanjing 210044,China;School of Atmospheric Physics Nanjing University of Information Science and 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,南京210044 [2]南京信息工程大学大气物理学院,南京210044 [3]中国科学院空间天气学国家重点实验室,北京100190

出　　处：《地球物理学进展》2022年第6期2251-2257,共7页Progress in Geophysics

基　　金：国家自然科学基金(41974073,41404053);科工局民用航天预研项目(Nos.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资助编号: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：我们利用千年时间尺度的全球地磁模式CLAS10K.1b和CALS3K.4计算和分析了公元前10000年(10000 BC)至公元1900年(1900AD)中国大陆非偶极子(ND)磁场的时空变化,还考察了ND场和ND场Z分量的功率谱.以地磁ND场垂直分量Z为例,结果显示10000 BC—1900 AD期间,ND场有三个主要的变化期.10000 BC—2500 BC期间,正值区几乎占据了整个大陆;在2500 BC—1500 AD期间,正值区域变成负值区域.1500 AD—1900 AD,负向区域变为正值区域.东亚地区ND场的磁异常最早出现在1682 AD,其极值强度在研究期间总共增加了18128.73 nT,自1682年以来,极值位置一直向东南移动.ND场Z分量的平均年变率也可分为3个阶段,随时间共增加了56.45 nT/a.球谐阶数截断至N=3时东亚ND场磁异常区已基本形成,N>5时磁异常极值位置基本固定在44°N和103°E,强度随阶数增加而不断增强.功率谱表明,ND场的功率变化主要受Z分量功率的影响.We calculate and analyze the variations of Non-Dipole(ND)magnetic field in millennium scale over Chinese mainland during 10000 BC—1900 AD by using the newest global geomagnetic model,CLAS10 K.1 b and CALS3 K.4.Taking component Z as example.Main results show that there are 3 main variation periods of ND field during the study period.During the period from 10000 BC to 2500 BC,the positive area almost occupied the whole continent,then positive value area becomes the negative value area during 2500 BC—1500 AD.Thereafter,negative area becomes positive area.The magnetic anomaly of ND field over East-Asia firstly emerged in 1682 AD,whose extreme intensity has totally increased 18128.73 nT until 1900 AD,the extreme location has been moved southeastward since 1682 AD.Mean annual change of Z can be generally divided also into 3 phases.The amplitude of mean annual change totally increases 56.45 nT.The anomaly areas of ND field in East-Asia almost taken shape when spherical harmonic truncation level N=3,anomaly extreme locations almost fixed at 44°N and 103°E while N>5,and intensities continuously increase while degree increases.The power spectrum indicates that the power variation of ND field is mainly influenced by ND power of Z.

关 键 词：地磁场 非偶极子磁场 CALS10K.1b CALS3K.4 

分 类 号：P318[天文地球—固体地球物理学]