From 23:10 to 23:50 UT on 18 March 2004, the Double Star TC-1 spacecraft detected eight flux ropes at the outbound crossing of the southern dawnside magnetopause. A notable guide field existed inside all ropes. In the mean time the Cluster spacecraft were staying in the magnetosheath and found that the events occurred under the condition of southward IMF Bz and dominant negative IMF By. There are six ropes that appeared quasi-periodically, with a repeated period being approximately 1–4 min. The last flux rope lasts for a longer time interval with a larger peak in the BN variations; it can thus be referred to as a typical FTE. The 18 March 2004 event is quite similar to the multiple flux rope event observed by Cluster on 26 January 2001 at the northern duskside high-latitude magnetopause. A detailed comparison of these two events is made in the paper. Preliminary studies imply that both of these multiple flux ropes events seem to be produced by component reconnection at the dayside low-latitude magnetopause.

More than 40 gradual SEPs have been observed by GOES and SOHO from 2001 to 2003. During 12 SEPs of all these events, energetic electron ux enhancements with energies from 38 keV to 337 keV were observed by RAPID onboard Cluster spacecraft. During these 12 events the variation of the energetic electron ux measured by RAPID/Cluster was closely associated to the variation of the solar energetic proton ux. The observed energetic electron ux was independent on the location of Cluster in the magnetosphere and the background level of magnetospheric electrons (even when the Cluster spacecraft was crossing the magnetopause, the plasma sheet and the low latitude boundary layer). The similar variation of the enhancement of energetic electron ux has also been observed by POLAR and Geotail in some of these events. In some of these events, the electron measurement of RAPID/Cluster will not be contaminated by the SEP protons.

We show in this paper that intermediate shocks are formed from ki-netic Alfven waves through wave form continuous steepening. From the action of nonlinear interaction and dispersion Alfven solitons are formed and then evolve into shocks. We calculated the traveling stationary struc-tures directly from nonlinear autonomous equations which we had derived. These traveling stationary structures correspond to intermediate shock, switch-on shock or Alfven solitary waves. Another kind of rare discontinuity was discovered in the calculation from the rarefying solitary waves. The solitary wave series remain on the front of the shocks because of no strong dissipation appears in the equation. When we added some anomalous dissipation terms to the equations, intermediate shocks with increased in entropy appeared.

We present the temporal evolution of magnetic field topology in the magnetotail with a southward IMF in order to identify the magnetic reconnection. The magnetic field topology is uniquely determined by the eigenvalues of the critical points, if they are not degenerated. This is because the critical points, their number, and the rules between them characterize the whole magnetic field pattern. At the critical points, the magnetics become zero. The magnetic vector field curves and surfaces are both integrated out along the principal directions of certain classes of critical points including the Earth’s dipole magnetic field. The skeleton that includes the critical points, characteristic curves, and surfaces provides the three-dimensional topological structure of the reconnection. The change of the skeleton, i.e. the change of the topology, has revealed the occurrence of magnetic reconnection. Namely, threedimensional "X-points" or the more-than-two critical points that are saddle and connected each other are unstable and can move, vanish, and generated.