Characteristics Of Inner And External Geomagnetic Sq Current System In China

We calculated three-component Sq variations of 35 geomagnetic observatories for three geomagnetic seasons in China in 2009, and used spherical cap harmonic analyzing method to divide those Sq variations into inner and external two parts, then deduced their equivalent current system individually. We analyzed the seasonal characteristics of the two parts of geomagnetic current systems and obtained the following results. For external current system, in three Lioyd (D,E,J) seasons, respectively, the maximum intensity is 56. 2 kA, 137. 7 kA, 137. 9 kA, and the LT of the current vortex is displaced from 1124LT to about 1030 LT. For inner current system, in D, E, J season, respectively, the maximum intensity is 21. 1 kA, 63. 4 kA, 72. 7 kA, and the LT of the current vortex is displaced from 1100 LT to about 1000 LT.