Unusual heating events at about 250 km altitude at very low latitudes seen by AE-E

Abstract

Simultaneous in situ measurements were made by a number of instruments on board the Atmosphere Explorer E (AE-E) satellite of the densities and temperatures of neutrals and ions and wind velocity transverse to the orbital direction. In a near circular orbit inclined 20° and at about 250 km altitude in 1977, during periods of magnetic activity, perturbations were observed at very low latitudes for a limited range of longitudes in the distribution along the orbit of oxygen, nitrogen, helium, argon and electron density and temperature, neutral and ion temperatures and the north-south winds. These perturbations appear like those seen in auroral regions in the thermosphere at the some altitude where heat is deposited due to precipitation and currents. The explanation is that localized heating was occurring by some means. Possible sources for this heating are considered.