This brief report presents the latest advances of the magnetospheric physics researches in China during the period of 2002-2004. The progress of the magnetospheric space mission DSP is given in another dedicated paper of this issue.
Based on satellite observation data, using dynamics equation, the ionospheric O+ ions distribution in the synchronous altitude region for different geomagnetic activity index Kp is studied by theoretical modeling and numerical analyzing, and semi-empirical models for the O+ ions den-sity and flux versus longitude in the synchronous altitude region for different Kp are given. The main results show that in the synchronous altitude region: (i) The O+ ions density and flux in day-side are larger than those in nightside. (ii) With longitude changing, the higher the geomagnetic activity index Kp is, the higher the O+ ions density and flux, and their variation amplitude will be. The O+ ions density and flux when Kp ≥ 6 will be about ten times as great as that when Kp = 0. (iii) When Kp = 0 or Kp ≥ 6, the O+ ions density reaches maximum at longitudes 120°and 240°respectively, and minimum in the magnetotail. When Kp = 3—5, the O+ ions density gets to maxi-mum at longitude 0°, and minimum in the magnetotail. However, the O+ ions flux reaches maxi-mum at longitude 120°and 240°respectively, and minimum in the magnetotail for any Kp value.
