Observation of Precipitating Electrons on Board the S-310JA-2 (a. Precipitating Particles and Auroras) (Proceedings of the First Symposium on Coordinated Observations of the Ionosphere and the Magnetosphere in the Polar Regions (Part I))

Abstract

A cylindrical electrostatic analyzer on board the Japanese Antarctic sounding rocket S-310JA-2 launched on February 10, 1977 at Syowa Station obtained the energy spectra of energetic electrons m the Antarctic polar ionosphere. The geomagnetic activity was high and there was a diffuse aurora at the time of launch. The measured electron flux was about l.8×10^3 electrons/cm^2・sec・str・eV at the energy of 4.2 keV and about 2.3×10^4 electrons/cm^2・sec・str・eV at 740 eV. The electrons whose energy was in the neighborhood of 500 eV had a considerable pitch angle dependence, and the field aligned current density due to these electrons resulted in about 1.47×10^ A/m^2.