| The dependence of Sq on space and time is analyzed based on the data recorded by the geomagnetic observatories all over the China. Furthermore, the new R-K relationship suitable for China mainland is also established. The results are as following.1. For a long time, only one R-K relationship (threshold value: 300) is used in China, which is not suitable for areas which large difference of latitudes (the maximum is about 40 degrees). Compared with the Kp Index and K Index which published by Japan, we found it is better to computer the K Index using two threshold values, that is, 330 for southern area and 350 for northern area with magnetic latitude 25 degree line as the boundary of them.2. The amplitude of daily variation of D component declines and its peak obviously delays from summer, equinox to winter. The daily variation of D shows normal phenomena of"one peak and one valley", but it turns out to be"valley-peak-valley"in winter. At the same time, the first valley strengths and the second valley become disappeared from north area to south area.3. The path of Sq center is derived from the daily variation of H component at local time 11 a. m., which has the less amplitude compared to the average value. The amplitude of H declines from both south and north side towards the Sq center. The daily variation recorded in the southern area of the path of Sq center seems inverse to that recorded in the northern area, and show positive value at local time 11 a. m.4. All the daily Z amplitude declines from south to north in summer, equinox and winter, and the amplitude in winter is obvious less than that in equinox.5. The Sq center goes along the line from Quanzhou, Guiyang, Xichang and Lasa to Shiquanhe in Equinox, and moves 5-10 degrees northward in Winter.6. Different from equinox, the Sq often shows more than one center. Moreover, The arrival time of Sq(H) center in equinox is earlier than that in winter, and it also takes longer time to reach it.
|
PDF Full Text Request