A UNIFIED THEORY OF IONOSPHERE-PLASMASPHERE TRANSPORT OF SUPRATHERMALELECTRONS

We present a model of suprathermal electrons in the ionsophere and pla smasphere based on a solution to the kinetic equation along the entire length of a closed magnetic field line, that is, simultaneously for t he two conjugate ionospheres and the plasmasphere. We call this the un ified approach. It allows the determination of the distribution in ene rgy and pitch-angle of photoelectrons along the complete length of the field line thereby avoiding the introduction of artificial boundaries between the ionosphere and magnetosphere and, consequently, avoids pr oblems introduced by the uncertainty of these boundary conditions. In addition, it automatically accounts for backscattered electrons in the atmosphere and plasmasphere, and avoids splitting photoelectrons into a loss-cone and a trapped population. The method is not limited to sp ecific situations such as conjugated sunrise or symmetrical illuminati on of hemispheres, but is equally applicable to arbitrary illumination conditions.