A study of the magnetic field annihilation process in the magnetosphere and some geotechnical applications

Abstract

Our proposed project is to study the basic plasma processes associated with magnetic reconnection in the Earth's magnetosphere. The three-dimensional (3-D) reconnection process are emphasized in the present study. To explain the satellite observations of flux transfer events (FTEs), we have proposed a multiple X line reconnection (MXR) model for the dayside magnetopause. The same reconnection process may also explain the occurrence of geomagnetic substorms. The multiple X line reconnection is intrinsically a time- dependent process, featuring impulsive and intermittent magnetic reconnection. The study of driven magnetic reconnection process was further extended in the past year by our 3-D MHD simulations that magnetic reconnections may take place along the multiple X lines, resulting in the formulation of helical magnetic flux tubes. The simulation results confirm our earlier theoretical model of multiple X line reconnection in the real 3-D environment. The geometry of the reconnected field lines revealed in the 3-D simulations is found to be more complicated than anticipated. Strong plasma flows along the flux tubes is another feature observed in the simulations. The results suggested that the 3-D reconnections differ significantly from the 2-D reconnections.