SIMULATION OF COMPRESSIBLE VORTEX-INDUCED RECO-NNECTION AT THE DAYSIDE MAGNETOPAUSE REGION:THE FORMATION AND STRUCTURE OF FTES

By using a two-dimensional compressible MHD model, the local reconnection processes at the dayside magnetopause region are simulated based on the theory of vortex-induced reconnection. This process is: first, a fluid vortex is formed, which in turn, induce the reconnection so that a magnetic vortex is formed, and finally there will be a magnetic fluid vortex (MFvortex), of which the three-dimensional structure is a MFvortex tube. The MF vortex tube connectes the magnetosheath and the magnetosphere region. The compressible model is compared with the incompressible model, it is found that the growth of vortices under incompressible condition is faster than that for compressible condition, but the forms of vortices are analogous. It is thought that vortes-induced reconnection is an important machanism of flux transfer events (FTEs) formation, and the FTE tube is a MF vortex tube. The signatures of the magnetic field, velocity, density, temperature, and pressure of the FTEare simulated. The simulation results are consistent with observational examples of FTES.