Abstract

The flux of accelerated electrons in inverted V structures (as it was verified in many experimental observations) has the linear dependence from the field-aligned potential drop. Such a dependence cannot be obtained if the plasma sheet electron temperature considerably changes on the scale of the inverted V structure. Analysis of electron temperature distributions within the whole auroral oval (central plasma sheet ionospheric projection) has been made using the Intercosmos-Bulgaria-1300 polar orbiting satellite. It is shown, that the temperature obtained taking into consideration acceleration of precipitating electrons by a field-aligned potential drop, is nearly constant in the meridional direction and has no longitudinal dependence during quiet geomagnetic time. The results of observations are interpreted as a consequence of stochastic plasma sheet electron dynamics and plasma mixing. It is suggested that the electron motion in electric fields with scales comparable to the electron Larmor radius is the source of stochastization. The results provide constrains on the applicability of a number of theories of tail reconnection. © 1999 COSPAR. Published by Elsevier Science Ltd.