地磁场水平梯度及高空地磁场的计算与分析  

Calculation and analysis of geomagnetic field horizontal gradients and high altitude geomagnetic field

作　　者：冯彦[1] 蒋勇[1] 孙涵[2] 安振昌[3] 毛飞[4] 柳士俊[5] 

机构地区：[1]南京信息工程大学数学与统计学院,南京210044 [2]国家卫星气象中心遥感应用试验基地/广西气象减灾研究所,南宁530022 [3]中国科学院地质与地球物理研究所,北京100029 [4]中国气象科学研究院,北京100081 [5]中国气象局培训中心,北京100081

出　　处：《地球物理学进展》2013年第2期735-746,共12页Progress in Geophysics

基　　金：国家自然科学基金(41174165);国家公益性行业(气象)科研专项(GYHY200906033、GYHY201306073)联合资助

摘　　要：本文以2000.0年中国地区的实测数据为例,首先利用5阶Taylor多项式方法建立了各分量的地磁模型,接着对模型中各分量的纬度和经度进行微分,计算得到各分量的水平梯度值,并绘制了相应分量沿南北方向和东西方向的水平梯度分布图,最后通过Zmuda多项式方法,基于地面模型值以及水平梯度值计算了高空(100km)的各分量磁场值,并分析了水平梯度分布规律以及各分量随垂直高度的变化.结果表明:地磁场北向分量X、垂直分量Z、总强度F和磁倾角I分量的水平梯度主要随纬度变化,其中X、Z和F分量随纬度减少而梯度降低,东向分量Y和磁偏角D分量的水平梯度不仅随纬度变化,而且随经度变化,F分量的南北向梯度值在我国中心地区最大.在垂直方向,X、Z和F分量的强度分别随高度的上升而近似线性减小,在100km高度处,强度变化平均值分别为-4.629nT/km、-15.368nT/km和-16.226nT/km,Y分量强度随高度上升而呈近似线性增加,其平均变化值为0.166nT/km,而D和I分量基本不发生变化.Based on measured data over China in 2000. 0, each component model of geomagnetic field was derived by Taylor polynomial with degree 5 firstly, then the differential method for latitude and longitude of models was carried out to calculate the horizontal gradients of north-south and west-east direction respectively, whose corresponding gradients distribution maps of each components were drawn as well. Finally, high altitude （100 km） geomagnetic field values of each component were calculated by Zmuda method based on earth surface data and horizontal gradients, moreover, the analyses of distribution regulation of horizontal gradients and vertical variations of each component were analyzed numerically. Results showed that the horizontal gradient of northern component X, vertical component Z, total intensity F and inclination I mainly changed with latitude, horizontal gradients of component X, Z and F decreased while latitude decreased, eastern component Y and declination D varied with both latitude and longitude, horizontal gradients in north-south direction of F was the biggest in the central region of China. In vertical direction, intensities of X, Z and F were quasi linear decreased while altitude increased, whose mean variation values at 100km were -4. 629nT/km, -15. 368 nT/km and -16. 226 nT/ km, intensities of Y was also quasi linear increased while altitude increased, whose mean value was 0. 166 nT/km, D and I were almost invariable.

关 键 词：Taylor多项式 地磁场 水平梯度 Zmuda方法 

分 类 号：P318[天文地球—固体地球物理学]