ESA Science & Technology - Publication Archive

A statistical survey was performed on ion moments (including data on bulk velocity, ion beta, the ratio between the ion pressure and magnetic pressure, and ion temperature anisotropy) near the plasma sheet boundary layer and the immediately adjacent outer central plasma sheet, using four months of tail data obtained by the three-dimensional plasma instrument aboard the AMPTE/IRM satellite. It was found that there is a sharp gradient in ion density and ion beta at the interface between the plasma sheet boundary layer and the central plasma sheet. Average flow velocities in the plasma sheet boundary layer were found to be surprisingly low, typically below 100 km/sec.