Sq外源和内源电流体系的经度效应和UT变化  

LONGITUDINAL EFFECTS AND UT VARIATIONS OF THE Sq EXTERNAL AND INTERNAL CURRENT SYSTEMS

作　　者：徐文耀[1] 李卫东[1] 

机构地区：[1]中国科学院地球物理研究所

出　　处：《地球物理学报》1994年第4期440-447,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金

摘　　要：根据ＩＧＹ／ＩＧＣ期间全球地磁台网以及中国地磁台站的资料，计算出每－ＵＴ小时的Ｓｑ外源和内源电流体系．对Ｓｑ电流体系ＵＴ变化和经度效应的分析研究表明，Ｓｑ外源电流体系的空间图案没有显著的ＵＴ变化，电流涡焦点的地理纬度与磁赤道有密切关系，其变化范围，北半球为２５°－３５°Ｎ，南半球为３０°－４２．５°Ｓ．外源电流总强度的平均值为２２９ｋＡ（北半球）和１７３ｋＡ（南半球），其变化范围为±５０ｋＡ（北半球）和±４０ｋＡ（南半球）．Ｓｑ内源电流体系的图案和强度有显著的ＵＴ变化，电流体系焦点纬度有类似于外源电流系的变化．在大西洋、印度洋、北太平洋地区，内源电流体系的总强度明显小于大陆地区的内源电流强度，表明这些大洋地区上地幔电导率低于大陆地区．The Sq external and internal current systems have been calculated for each UT hour on the basis of the magnetic data from the world station network and China stations during IGY/IGC. The longitudinal effects and UT variations of the current systems have been analysed.For the external current System,there is no significant UT-variation in the pattern;the geographic latitudes of the current vortex foci are correlated with the magnetic equator with a variation range of 25° 35°N for Nhemisphere and 30° 42.5°S for S-hemisphere;the total intensity of the externalcurrent is 229kA for N-hemisphere and 173kA for S-hemisphere. For the internal current system the pattern and intensity have remarkable UT-variations;the focus latitude variation is similar to the external currents.In Atlantic,Indian Ocean,North Pacific Ocean,the intensities of the internal currents are smaller than those in continental regions,implying lower conductivities of the upper mantle in ocean regionsthan those in continents.

关 键 词：Sq电流体系 经度效应 UT变化 地磁 

分 类 号：P318.6[天文地球—固体地球物理学]