A particle simulation of flux transfer events at the earth's magnetopause

The flux transfer events observed by ISEE satellites indicated that the dayside magnetic reconnection geometry is different from that in Dungey's (1961) single-X-line model. The multiple-X-line reconnection process proposed by Lee and Fu (1985) seems to explain the flux-transfer events observed at the dayside magnetopause. Here, the multiple X-line reconnection by computer simulations based on a two-dimensional magnetostatic particle code. A driven boundary condition is applied at the two sides of the simulation domain with an incoming plasma flow while a free boundary condition issued at the other two sides with an outflow. Repeated formation and convection of magnetic islands are observed in the simulation. Magnetic islands with various sizes are observed. Particles are found to be heated during the reconnection process. The convection speed of the island may exceed the Alfven speed. The recurrence time of magnetic islands is found to be 5-15 min. These results are consistent with satellite observations of flux transfer events. Superthermal ions with energy of 1-50 keV are found to be present during the multiple-X-line reconnection process.