The magnetosphere is very dynamic. Magnetospheric substorms occur every few hours. Viewed from the Earth they are visible as auroral displays. In space one of the main phenomena associated with magnetospheric substorms is the generation of dipolarization fronts. These are rapid increases in the component of the magnetic field normal to the plasma sheet that propagate from the magnetotail toward the Earth. They are called dipolarization fronts (DFs) since the magnetic field assumes a more "dipole like" configuration. The most common explanation for DFs is that they are related to magnetic reconnection. This work is relevant to other studies of current sheets such as those in planetary magnetospheres, the solor corona and the solar wind.
The goal of this proposal is to investigate the formation of DFs in realistic tail models. The team proposes to construct new classes of self-consistent 2D current sheet equilibria similar to those observed during the growth phase of substorms. They will investigate their stability to reconnection by using kinetic theory and 2D particle in cell (PIC) simulations with realistic electron to ion mass ratio. This will be extended to 3D PIC simulations to investigate the whole spectrum of tail plasma responses including tearing, ballooning/interchange and flapping motions. The kinetic picture will be compared with that from global magnetohydrodynamic models with the goal of including the kinetic physics in the global models.
The Applied Physics Laboratory has a program for summer students to help with the research.
