The Near Earth Plasma Sheet - an AMPTE / IRM Perspective

During the last five years, statistical studies using plasma measurements made by the AMPTE/IRM satellite have lead to a better understanding of the structure and dynamics of the near-Earth plasma sheet between about 10 and 20R _E. The most notable new findings are: (1) the adiabatic non-isentropic behavior of the tail plasma during quiet times; (2) the strong non-adiabatic heating of ions and electrons during substorms and the strong coupling of the ion and electron temperature withT _i/T_i∼7; and (3) the high-speed flow bursts which carry most of the tail plasma transport. Moreover, it became clear that it is the central plasma sheet, and not the plasma sheet boundary layer, which is most affected by substorm activity.