Plasma Convection in the Vicinity of the Geosynchronous Orbit

Abstract

An analytic function respresenting the quiet time magnetospheric electric field has been constructed with which it is possible to compute complete particle trajectories in a fraction of a second. The function was determined by a trial-and-error procedure such that it provides reasonable explanations for the characteristics of the plasma observed by the geosynchronous satellite ATS 5. It is believed that the model field is usefully accurate within the region of 5 to 7 earth radii on the dawn side of the magnetosphere and 5 to 10 earth radii on the dusk side. At a fixed distance of 6.7 earth radii the model field peaks at a value of 1.2 mV/m near local midnight and is at a minimum of 0.04 mV/m near 1900 LT.