The Inner Edge of the Plasma Sheet

The plasma properties at the inner edge of the ion and electron plasma sheets are analyzed as functions of solar wind drivers. Low-altitude observations by DMSP provide frequent encounters with the ion and electron inner edges taken as the equatorward edge of the respective diffuse precipitation. Energy spectra are fit to various distributions. The focus is on large-scale plasma sheet properties so lower energy populations are ignored (they appear to be small-scale transients). Maxwellian, kappa, linear and Ellison-Ramaty distributed spectra are considered. Non-thermal distributions are found roughly 15% of the time, depending on activity. The dependence of the spectral type, pressure, density and temperature, on solar wind driving is assessed. The relationship between the high- and low-altitude portion of the plasma sheet's inner edge is examined by comparing DMSP boundaries with simultaneous THEMIS boundaries. Statistical results, as well as examples from high speed streams, will be presented.