A model of auroral potential structures based on Dynamics Explorer plasma data

Dynamics Explorer 1 hot plasma data are used to investigate three major features of the mid-altitude auroral electron distribution -- the hole, the bump (at large pitch angles), and the loss cone. The results of a computer simulation show that these features can be approximately reproduced by a model involving an initial plasma sheet electron distribution and two potential drop regions that are widely separated in altitude. The observed distributions could not be reproduced, even qualitatively, by any of a wide range of distributed potential drops involving parallel electric fields at the point of observation.