Comprehensive Mappings of Electron Precipitation and its Effects on the Atmosphere

Precipitation of energetic electrons is an important energy input to the earths upper atmosphere and can alter the chemistry and dynamics of that region. The precipitation can be studied on a global basis using a satellite X- ray imager to make maps of the X-rays produced when the electrons stop in the atmosphere. We have used 4-40 keV X-ray data from the S81-1 SEEP satellite instrument to classify the patterns of precipitation at high latitudes the three principal types are strong auroral arcs an the night side, extended dawnside arcs, and isolated pitches inside the polar cap. We also studied the characteristics of high energy relativistic electron precipitation with data from instruments that directly detect the electrons. This very penetrating radiation is important because the electrons deposit their energy down to altitudes as low as - 55 km. This study found that the precipitation was confined to narrow latitude bands, often at the outer boundary of the belt of trapped electrons, and that it occurs more often at midnight local time than at noontime. X-ray mappings, relativistic electrons, electron precipitation, effects on the atmosphere.