Ground magnetic characteristics of the storm-time ring current Asymmetry  

作　　者：WU YingYan XU WenYao CHEN GengXiong CHEN Bo LIU XiaoCan 

机构地区：[1]Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Graduate University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Earth Sciences》2008年第5期686-693,共8页中国科学（地球科学英文版）

基　　金：the National Basic Research Program of China (Grant No. 2006CB806305);National Natural Science Foundation of China (Grant No. 40436016)

摘　　要：Using the minute data of the H component of geomagnetic field from the 20°E magnetic meridian chain and the 30°N magnetic latitudinal chain, the temporal evolution characteristics of the equatorial ring current during the storm on November 7-10, 2004 are studied. It is indicated that the UT-MLT and UT-MLAT graphics extremely exhibit the local time distribution, latitudinal variation and temporal evo- lution of the H component. The results show: (1) The UT-MLT contour clearly shows the increasing of the H component mostly around noon during the initial phase, representing the geomagnetic effect from the magnetopause current system. During the main phase, most negative values of the H com- ponent appear around the dusk-side, indicating the dawn-dusk asymmetric distribution of the ring cur- rent. (2) The contour of UT-MLAT suggests the latitudinal variation of the H component decreasing with the enhancement of the latitudes during geomagnetic storm, which is in good agreement with the Dst index. The latitudinal variations provide a new sight for describing the temporal characteristics of the intensity of the storm-time ring current. (3) Both the contours of UT-MLT and UT-MLAT are useful to monitor the space-time distribution of the equatorial ring current.Using the minute data of the H component of geomagnetic field from the 20°E magnetic meridian chain and the 30°N magnetic latitudinal chain, the temporal evolution characteristics of the equatorial ring current during the storm on November 7–10, 2004 are studied. It is indicated that the UT-MLT and UT-MLAT graphics extremely exhibit the local time distribution, latitudinal variation and temporal evolution of the H component. The results show: (1) The UT-MLT contour clearly shows the increasing of the H component mostly around noon during the initial phase, representing the geomagnetic effect from the magnetopause current system. During the main phase, most negative values of the H component appear around the dusk-side, indicating the dawn-dusk asymmetric distribution of the ring current. (2) The contour of UT-MLAT suggests the latitudinal variation of the H component decreasing with the enhancement of the latitudes during geomagnetic storm, which is in good agreement with the D st index. The latitudinal variations provide a new sight for describing the temporal characteristics of the intensity of the storm-time ring current. (3) Both the contours of UT-MLT and UT-MLAT are useful to monitor the space-time distribution of the equatorial ring current.

关 键 词：GEOMAGNETIC STORM RING current dawn-dusk asymmetry latitudinal VARIATION 

分 类 号：P318[天文地球—固体地球物理学]