1900年以来地磁场西向漂移的全球特征  

Global Changes of the Geomagnetic Westward Drift Since 1900

作　　者：康国发[1] 胡家富[1] 翟应田[2] 徐慧[3] 

机构地区：[1]云南大学地球科学系,云南昆明650091 [2]云南大学物理系,云南昆明650091 [3]云南大学实验中心,云南昆明650091

出　　处：《云南大学学报（自然科学版）》2000年第4期297-301,共5页Journal of Yunnan University(Natural Sciences Edition)

基　　金：云南省自然科学基金资助项目!( 98D0 0 4G)

摘　　要：根据最新公布的第 7代国际地磁参考场模型 (IGRF) ,用 4种方法计算 190 0～ 2 0 0 0年的地球磁场的西漂 ,分析西漂的时间变化规律和不同纬度圈的漂移特点 .结果表明 ,不同的方法得出的漂移速度有一定差异 .西漂主要是非偶极子磁场产生 ,低阶球谐项平均西漂大 ,其中 2阶项最大 ,高阶球谐项西漂小 .西漂的地理分布特征是北纬 40～ 80°N和南纬 70～ 80°S之间西漂速度较小 ,0～ 6 0°S之间西漂速度较大 .Based on the seventh generation of International Geomagnetic Reference Field models,the westward drift of geomagnetic field for 1900—2000 were calculated by using four methods and analyzed the variation features of with time and different latitudes.The results show that there were difference the drifting velocity of using different methods.The westward drift was mainly caused by nondipol magnetic fields.The average drifting velocity was large in low degree harmonic components and was small in high degree terms.The geographic distribution of westward drift were large in 40—80°N and 70～80S and were small in 0—60°S.

关 键 词：地磁场 西向漂移 国际地磁参考场模型 地理分布 

分 类 号：P318[天文地球—固体地球物理学]