One of the critical regions of the magnetosphere is the magnetotail, which is thought to be responsible for magnetospheric substorms, which are intervals of time that are associated with enhanced currents and intensification of the auroral (i.e. northern lights). This grant concentrates on three problems concerning the plasma physics of the magnetotail: 1) the origin of mid-frequency electrostatic plasma waves, 2) collisionless tearing mode reconnection in teh closed magnetic field-line region of the plasma sheet, and 3) the structure of collisionless shocks in the distant tail. These problems will be attached using observations, analytic theory and numerical simulations.
