Cause of X-Line Formation in the Near-Earth Plasma Sheet: Results of Adiabatic Convection of Plasma-Sheet-Plasma

摘要

Self-consistent, static-equilibrium solutions are presented for two-dimensional magnetospheric-magnetic-field configurations with isotropic thermal pressure. These solutions include a dipole field and are not restricted to the asymptotic theory. Adiabatic convection of plasma sheet flux tubes is modeled as a series oif static-equilibrium solutions in which flux tubes conserve their PV(gamma) as they convect, which resulted in time dependent magnetospheric configurations. Specifically, it is found that a deep minimum in the equatorial B sub z develops in the inner plasma sheet, thereby causing the magnetic-field configuration to become more stretched and tail-like in time. These results suggest X-line formation in the inner plasma sheet as a consequence of lossless, adiabatic convection of plasma sheet flux tubes. (Author)