Nonlinear kinetic modeling of early stage plasmaspheric refilling

A new time-dependent kinetic model is used to investigate the effects of se lf-consistency and hot plasma influences on plasmaspheric refilling. The mo del employs a direct solution of the kinetic equation with a Fokker-Planck Coulomb collision operator to obtain the phase space distribution function of the thermal protons along a field line. Of particular interest is the in fluence of several processes on the source cone distribution function forma tion. It is found that a self-consistent ion temperature in the collision t erm can increase or decrease the equatorial plane density, depending not on ly on the choice of ion temperature in the static-background calculations b ut also on the form of the nonlinear representation. The inclusion of a sel f-consistent polarization electric field increases the early stage equatori al plane density by a factor of 2. Investigations of the effects of anisotr opic hot plasma populations on the refilling rates shows that, after a slig ht initial decrease in equatorial density from clearing out the initial dis tribution, there is a 10 to 30% increase after 4 hours due to these populat ions. This increase is due primarily to a slowing of the refilling streams near the equator from the reversed electric field.